Is my PCV bad?

[muffinman92]

Hello all, I've had some recent issues with my B8.5 Allroad that I need some help with.

Two Nights ago:

Really high boost showing on gauge
Car drives but is really slow compared to before

Yesterday:

Car drives better and builds boost/power more normal but I get a P2187 Code
Idles fine, and when I cleared the code it did not come back.


Is this my PCV starting to go out?

[S-Liner]

Is the PCV pissing air out of the small port facing towards the firewall? Also an air leak somewhere in the system will cause a lean condition. Check your fuel trims as well

Some FYI...I got the same code, my Avant idles fine and builds boost just fine. No air leaks anywhere. I believe my short and long trims are in line. Once I clear it, it will come on only on hard acceleration

I’m thinking fuel injector(s)




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[Depthcharge]

How many miles? Around 80k users have reported injectors having some issues.

[Spawne32]

easy way to tell, its either leaking air near the diaphragm on the top of the PCV like S-liner said, or pop your oil cap off with it running and if it tries to suck your hand in the engine then you know.

[muffinman92]

Follow up. I swapped out the PCV Diaphram to start with the cheapest of solution. No luck. Car popped the same code again. Car drives fine but under heavy boost will sometimes be much slower than others. No choppiness or misfires, which if there were would help point out it being an injector or fuel pump issue. No exhaust leaks, checked under the car and everything is good.

Here is a video to show the new PCV Diaphram on there. Can't hear any leaks. When I take the cap off it idles rougher, not sure if that is normal or due to a bad PCV. Car has 73xxx miles.


https://youtu.be/E3_6eLNmZBw

Possible P2187 Issues:

Full PCV is bad - I think the PCV is okay
Front or Rear Main Seal - How would I check this?
Boost leak - I had removed my Intake Manifold/Throttle Body a few months ago to change my coolant pump. I did not change the gaskets. I sprayed soapy water all around but so no leaks. Could this be it?
Exhaust Leak - Checked exhaust and all is fine
Injectors/Fuel Pump - I have no other codes to indicate this and do not have rough idles, choppines, or misfires


This was the old Diaphragm, looked fine to me.

https://i.ibb.co/Y7nSTLn/Photo-Aug-15-7-08-53-AM.jpg (https://ibb.co/QFSVjKS)


HELP!

[Theiceman]

im not sure what boost has to do with the PCV . maybe there is a system i dont understand...
if you over boosted i would imagine car went into limp mode. i would be thinking more n75 or pressure sensor not reading correct boost to ECU or diverter valve or somthing.

[muffinman92]

im not sure what boost has to do with the PCV . maybe there is a system i dont understand...
if you over boosted i would imagine car went into limp mode. i would be thinking more n75 or pressure sensor not reading correct boost to ECU or diverter valve or somthing.

It is the P2187 code that is directing me towards that.

[Theiceman]

you didnt tell us what that is.

[muffinman92]

you didnt tell us what that is.

It is a well known code.

P2187 (System Too Lean at Idle Bank 1)

[Theiceman]

system too lean id be checking for un-metered air someplace .. if it is not obvious make sure it is not coming from the gas tank evap system, a cu t line will obviously draw air. Not common for HPFP or injectors to fail this way but fuel trim might tell you something compared to spec.

[muffinman92]

system too lean id be checking for un-metered air someplace .. if it is not obvious make sure it is not coming from the gas tank evap system, a cu t line will obviously draw air. Not common for HPFP or injectors to fail this way but fuel trim might tell you something compared to spec.

So most likely a boost leak somewhere? Would I do a smoke test to find this?

[Theiceman]

i dont think so .. this is lean at idle.. there is no boost at idle... but yeah i think i know what you are saying.. more likely a cut vacuum line or evap line somewhere...

i am actually going to build my own boost leak tester off another thread.. mat be hard to find with smoke but you nebver know .. if you have a boost gauge you should be able to see idle vacuum.. maybe compare to someone

[muffinman92]

If it was just lean at idle could this be a leak in the intake manifold as mentioned? We had removed both the throttle body and intake manifold to get to my coolant pump, and did not use new gaskets when replaced. Would this be the culprit?

[Theiceman]

Ok now we get the added info.
How long ago was this work. If you were in the area recently you may have to redo what you did.
I would redo it all if this cropped up immediately after.

If it was just lean at idle could this be a leak in the intake manifold as mentioned? We had removed both the throttle body and intake manifold to get to my coolant pump, and did not use new gaskets when replaced. Would this be the culprit?

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[S-Liner]

Well, a bad diverter valve could show/give a lean condition fault

Do you know which revision you have or if it’s ever been replaced? If it’s the older type with the rubber in it. It may be torn considering the mileage you got

RMS? Any oil leaks underneath?

*I’ve removed and reinstalled my intake manifold numerous times now—never changed out the gasket. It’s all in the torque sequence

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[Theiceman]

How ?
I was under the impression a diverter is used to divert air back into the intake that has already been accounted for.
How does it cause lean condition ? Unless it is ruptured of course and let's unmetered air in.
Well, a bad diverter valve could show/give a lean condition fault

Do you know which revision you have or if it’s ever been replaced? If it’s the older type with the rubber in it. It may be torn considering the mileage you got

RMS? Any oil leaks underneath?

*I’ve removed and reinstalled my intake manifold numerous times now—never changed out the gasket. It’s all in the torque sequence

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[maquino]

You sure it’s not the turbo waste gate problem?

[bb-tt]

N80 potentially? Did you check all vacuum lines and boost hose / intake track after maf for leaks?

[jc_B8_A4]

If you do find the issue to be the diverter valve i have the piston style one for sale :)


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[Smac770]

He got a lean at idle fault, but cleared it and it went away, no? Has it come back? Checked values to see what the long term mix and idle trims are? Are they high lean, or do they seem normal and it was a fluke event? To get the error, you need to be +25% trim, no?
The trigger observation is this "boost was high". Using what boost gauge, as the car displays none by default. Where is the boost value being measured? High relative to what expectation? B8.5 factory is 17psi max boost, iirc. Excess boost sounds more like a turbo problem, either actuator or diverter operation problem. Is your car in any way not normal stock?
If you were wondering about the PCV, I assume you'd need a combination gauge on the dipstick and on the intake manifold (such as a boost tap on the PCV connection) and see how pressures in the crankcase and manifold are during idle and during 2k revs (better yet, as you drive). Are the pressures as expected or not? Or the simple version, if your trims are lean, block off the PCV-manifold connection and see if they normalize out. If not, then it's not from spare air from wherever through the PCV into the manifold.
You have to check the EVAP lines; it makes the same bridge between the turbo inlet and intake manifold using check valves they may or may not falter.

[S-Liner]

For it to pop a lean condition, the rubber seal in the diverter valve has to be completely shredded. It’s an audible sound too, that fluttering noise as you let off the throttle as well as feeling it with a very obvious power decline. I think there’s a YouTube video of that bearded VW dude talking about failure points with the valve.


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[Theiceman]

For it to pop a lean condition, the rubber seal in the diverter valve has to be completely shredded. It’s an audible sound too, that fluttering noise as you let off the throttle as well as feeling it with a very obvious power decline. I think there’s a YouTube video of that bearded VW dude talking about failure points with the valve.


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i think " that bearded dude" is humble mechanic.

[muffinman92]

Hello all,

The car has the following

CTS K04
CTS Test Pipe
IE Intercooler
ECS Intercooler Piping
AFE Filter
Red Top Coil Packs
1 Step Colder Plugs
GFB Diverter Valve

I have read that the GFB Diverter Valve can have problems over time. Not sure if this would be related to the code though. It would explain my boost issue that comes and goes. The CEL has come on again after clearing, but does not come on right away. Took a lot more driving to pop. The intake manifold was taken off a couple thousand miles ago and did not have this issue. So not sure if it is related. The car is a 2013 Allroad so I believe the flex fuel engine is a bit different than the average A4, as it has the 5th injector, different fuel pump, a metal intake manifold.

[Spawne32]

Only way you would throw that code is if the air was coming in AFTER the throttlebody. So you have to check for leaks around the gaskets, and the vacuum hoses, and or PCV. If the diaphram on the PCV is torn, you can upgrade it using the RKX 2.0T diaphram which is fiber reinforced fluorosilicone. The dorman one will only last....20k? https://www.amazon.com/RKX-2-0T-INDESTRUCTIBLE-valve-upgrade/dp/B07N8H61VN

[muffinman92]

Only way you would throw that code is if the air was coming in AFTER the throttlebody. So you have to check for leaks around the gaskets, and the vacuum hoses, and or PCV. If the diaphram on the PCV is torn, you can upgrade it using the RKX 2.0T diaphram which is fiber reinforced fluorosilicone. The dorman one will only last....20k? https://www.amazon.com/RKX-2-0T-INDESTRUCTIBLE-valve-upgrade/dp/B07N8H61VN

Is there a way to check for leaks? Would the old carb cleaner trip work?

[Spawne32]

Is there a way to check for leaks? Would the old carb cleaner trip work?

Absolutely, carb clean, brake clean, real easy way to check. The diaphragm usually causes a whistling out of a little port hole in the front of it, or an insanely high amount of crankcase vacuum. The problem is that when that happens it usually sucks the RMS inside out. lol That's how you wind up with a leaky RMS and a constant vacuum leak that can't be fixed unless you pull the engine. I'd honestly suspect a cracked hose or something, theres a series of hard plastic hoses that over the years get brittle and snap real easily. Theres a few under the intake manifold that lead to the purge solenoid.

[Spawne32]

I just saw your video, if the car idles rough when you take the cap off, its the PCV manifold itself.

- - - Updated - - -


https://www.youtube.com/watch?v=VZGYJYtkhPc

- - - Updated - - -

Soon as he takes the oil cap off, car stalls out. lol

[Theiceman]

I just saw your video, if the car idles rough when you take the cap off, its the PCV manifold itself.

- - - Updated - - -


https://www.youtube.com/watch?v=VZGYJYtkhPc

- - - Updated - - -

Soon as he takes the oil cap off, car stalls out. lol

im not so sure about that .... when you do that you create a vacuum leak. i am sure all our cars would run rougher with the oil cap removed while running.

[Spawne32]

im not so sure about that .... when you do that you create a vacuum leak. i am sure all our cars would run rougher with the oil cap removed while running.

try it, ive had my car running with the oil cap off, never had an issue. purpose of the PCV valve is to close off the crankcase at idle from engine vacuum. A more primitive PCV system was merely a check valve that would be sucked closed at high vacuum and open at low vacuum to vent the crankcase.

[Theiceman]

try it, ive had my car running with the oil cap off, never had an issue. purpose of the PCV valve is to close off the crankcase at idle from engine vacuum. A more primitive PCV system was merely a check valve that would be sucked closed at high vacuum and open at low vacuum to vent the crankcase.

will do ..

[muffinman92]

will do ..

Let me know what happens, because if this is the case it is my PCV. I thought the rough idle was normal with the cap off due to the vacuum being lost

[old guy]

Let me know what happens, because if this is the case it is my PCV. I thought the rough idle was normal with the cap off due to the vacuum being lost

When the engine is warmed up and at idle the PCV combi valve is pulling metered purge air from the inlet side of the turbo, through the block and into the intake manifold. The PRV portion of the combi valve (the diaphragm) regulates the amount of air being pulled. If you remove the oil filler cap you will begin to pull unmetered air into the intake stream and consequently the idle will get rougher.

If the PRV diaphragm is damaged you will be pulling full manifold vacuum on the block. So in that case you will have massive vacuum when you remove the oil filler cap and the engine will probably quit running altogether.

[muffinman92]

When the engine is warmed up and at idle the PCV combi valve is pulling metered purge air from the inlet side of the turbo, through the block and into the intake manifold. The PRV portion of the combi valve (the diaphragm) regulates the amount of air being pulled. If you remove the oil filler cap you will begin to pull unmetered air into the intake stream and consequently the idle will get rougher.

If the PRV diaphragm is damaged you will be pulling full manifold vacuum on the block. So in that case you will have massive vacuum when you remove the oil filler cap and the engine will probably quit running altogether.

Sounds like my PCV is fine then. In the video that I posted I took off the cap from the engine and the idle was rougher but still ran fine

[Theiceman]

Car stumbles badly when oil cap removed but does not stall. Brand new pcv on re built engine that is running great.
Buddies b8 exactly the same
Sons b7 that is running excellent Same.

Let me know what happens, because if this is the case it is my PCV. I thought the rough idle was normal with the cap off due to the vacuum being lost

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[Spawne32]

When the engine is warmed up and at idle the PCV combi valve is pulling metered purge air from the inlet side of the turbo, through the block and into the intake manifold. The PRV portion of the combi valve (the diaphragm) regulates the amount of air being pulled. If you remove the oil filler cap you will begin to pull unmetered air into the intake stream and consequently the idle will get rougher.

If the PRV diaphragm is damaged you will be pulling full manifold vacuum on the block. So in that case you will have massive vacuum when you remove the oil filler cap and the engine will probably quit running altogether.

I was under the assumption that the combi valve was regulated by spring pressure in the PCV, opening the cap should not increase the amount of air entering the engine/intake to cause the engine to stutter at all, as all it does is change the source of where the air is coming from. The airflow through the PCV shouldn't change regardless of the source of where the air comes from.

[old guy]

Once you open the cap the purge air source is coming from the cap rather than from the intake side of the turbo. The air from the intake side of the turbo has been metered by the MAF sensor. The air coming in through the cap has not. Consequently the engine leans out and stumbles.

[Spawne32]

Once you open the cap the purge air source is coming from the cap rather than from the intake side of the turbo. The air from the intake side of the turbo has been metered by the MAF sensor. The air coming in through the cap has not. Consequently the engine leans out and stumbles.

Right, but the system is supposed to maintain equilibrium via the diaphragm and spring using intake pressure/vacuum, hence why when the diaphragm fails the car doesn't run properly. You cannot have a system that pulls that much vacuum through the crankcase or you would cause premature gasket failure...then again, why I am surprised by this.

[Theiceman]

Right, but the system is supposed to maintain equilibrium via the diaphragm and spring using intake pressure/vacuum, hence why when the diaphragm fails the car doesn't run properly. You cannot have a system that pulls that much vacuum through the crankcase or you would cause premature gasket failure...then again, why I am surprised by this.I would assume this engine is designed for high crankcase vacuum. It is very significant on all 2.0t engines. Complete different to the somewhat neutral design of the 1.8t. My buddy was over last night with his 1.8 TT and the feel is surprisingly neutral.

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[Spawne32]

I would assume this engine is designed for high crankcase vacuum. It is very significant on all 2.0t engines. Complete different to the somewhat neutral design of the 1.8t. My buddy was over last night with his 1.8 TT and the feel is surprisingly neutral.

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german engineering is so bizarre lol

[old guy]

I have both a 1.8T and a 2.0T. The 2.0T operates with considerably higher crankcase vacuum.

[Smac770]

I made this doc for another reason, but it seems it might be useful here.
I've never measured my crankcase vacuum at idle (the common process seems to be to tape the gauge tube to the dipstick opening), but I measured 18 inHg in the manifold using a boost tap on the PCV-manifold line. This seems normal; most what I found said ~20. I have not found any docs noting the expected normal vacuum in the crankcase at idle; only that the diaphragm valve is the protector of the crankcase from excessive vacuum at the intake manifold or turbo inlet that would impact the oil seals.

One reference I used was https://www.briskoda.net/forums/topic/442333-20-tsi-pcv-suction-from-tiny-hole

In this document was a diagram that showed a modification to the EA888 Gen2 PCV (which is different from the EA888 Gen1 in regards to the breather tube and high pressure bypass implementation) to add an additional valve between the cyclone separator input and the cylinder head galley. I would have assumed that the cylinder head galley was joined with the crankcase galley from a pressure perspective. Ie, the oil filler hole, am I not pouring oil into the cylinder head galley and then it just drains down? Or is the oil filler hole actually an isolated path down to the oil path? But so I'm not sure if that's there on which of the Gen1, the Gen2 black cap, the Gen2 white cap, or the Gen3 (looks like the Gen3 added a port for the EVAP connection to the manifold too, rather than a separate EVAP opening on the manifold).

The pic has what I expect are the valves in their idle positions. The manifold vacuum is pulling down on the diaphragm valve somewhat, but not entirely closed (is my expectation; again, lacking details in any SSPs; the pressure management is regulated by the strength of the spring, ie black cap vs white cap difference, at least one of the differences). This vacuum cascades through the fine oil separator and coarse oil separator to the crankcase, where it opens the breather valve to pull in fresh air from the turbo intake.

When the diaphragm tears, the atmospheric pressure backing the diaphragm is sucked out (I assume the small hole to outside ambient prevents the atmosphere from winning the tug of war with the manifold vacuum) and now there's no loading on the spring, so the diaphragm valve is pushed wide open. This passes far more of the manifold vacuum to the crankcase, and we get the sucked on oil cap issue. It's less clear why pulling the oil cap or dipstick cap smooths the idle in this scenario (with a working PCV, pulling the oil cap or dipstick cap will of course create a rough idle, same as when the PCV diaphragm is torn and letting outside air in that way). I've actually done that when my PCV had a torn diaphragm; covering the PCV vent hole smoothed out the idle, but so did leaving the PCV vent hole whistling and pulling the dipstick cap. Covering the PCV vent hole and pulling the dipstick cap restored the rough idle; though, that makes sense at this point.

137012

[Spawne32]

Great explanation!

[old guy]

Some more visuals to go with the explanation:

These excerpts from the 2.0L 4V TFSI Study Guide explain the function of the PCV portion of the Crankcase Ventilation System.

https://i.postimg.cc/VsntpYmX/PCV-definition.jpg

This picture shows the location of the PCV combination valve in the Crankcase Ventilation System. It can flow air in two directions. When the intake manifold is under vacuum the PCV combination valve allows filtered, metered purge air to be drawn through the connection at the turbo inlet. This purge air enters the block and is then pulled out through the Crankcase Ventilation System into the intake manifold. The amount of negative pressure is being controlled by the Pressure Regulating Valve (large diaphragm).

When the block pressure exceeds the spring pressure in the PCV combi valve it will then open up and allow air to move in the opposite direction toward the turbo inlet to reduce the block blow-by pressure. Manifold pressure is blocked by the two non-return valves.
https://i.postimg.cc/vm5MMSB2/PCV-Valve.jpg

[Spawne32]

So do we know if the later revisions of the PCV manifold change the amount of crankcase vacuum at all?

[old guy]

So do we know if the later revisions of the PCV manifold change the amount of crankcase vacuum at all?

That s an excellent question. I have searched for quite some time looking for that answer. So far the only reference I can find is from this site Clicky-click® (http://karmakanix.com/knowledgebase/engines/gas-engines-vw-audi/2-0t-engine-tfsi-fsi-audi-vw/2-0t-oil-consumption-pcv-breather-valve/) and it refers to a EA888 Gen 3 engine.

"So what is the normal pressure in an engine crankcase? That depends on the engine speed and load, and varies with altitude and engine wear. Each engine is designed with different pressure parameters to control emissions as well as oil consumption. On the 1.8T and 2.0T EA888 Generation 3 engines, the pressure control valve inside the PCV breather valve is rated for a difference of -100 millibar (-1.45 psi or 2.93 “Hg) relative to the ambient air pressure. On a normal engine at idle, that will be the approximate negative pressure (vacuum) measured at the oil cap. The pressure will change slightly while driving. It can go slightly positive under load as the blow-by gases get redirected from the intake manifold to the turbocharger inlet. The crankcase should never experience either a high vacuum or a high pressure."

This doesn't answer the question about differences between different PCV combi valve revisions. If I ever come across anything I will be sure to follow up.

[Smac770]

That spec is the same as what's in the SSP 384 for the EA888 Gen 1.

The breather valve opens to allow fresh air flow (turbo inlet to crankcase) when the pressure difference (crankcase pressure - turbo inlet pressure) is 7 mbar or less. So when the turbo inlet goes negative during boost, the breather valve closes.
The safety valve opens to vent crankcase pressure (crankcase to turbo inlet) when the pressure difference (crankcase pressure - turbo inlet pressure) is 100 mbar +-15 mbar (1.3-1.6 psi roughly). But if the crankcase pressurizes pretty hard during boost, the turbo inlet is already at vacuum and pulling the fine oil separator output, rather than outside ambient. If the crankcase pressure is more than just 1.5 psi above that vacuum (not ambient; how would it know ambient pressure), then the safety valve would vent out to the turbo inlet, bypassing the coarse and fine oil separators.

So the safety valve is the pressure control valve against too high crankcase pressure, apparently limited to ~1.45 psi above the turbo inlet pressure (which is ambient at idle, but some amount of vacuum under throttle).
And the diaphragm valve is the pressure control valve against too high crankcase vacuum. But no specs about at what vacuum is necessary to fully close it.
https://www.audiworld.com/forums/a6-c7-platform-discussion-194/service-campaign-2011-2014-2-0t-pcv-2892721/

Short of someone talking a black cap and a white cap and actually testing the pressures on the various orifices and logging at what point things happen, I doubt we'll ever know for sure. But I'm not about to drop $300 "for science".

[Smac770]

If you have the Mityvac vacuum pump/gauge, the largest attachment piece fits into the dipstick hole just perfect.
The Mityvac combination (vacuum/pressure) pump/gauge lacks and scale markers between 5 inHg vacuum and 2 psi pressure, just calling it all zero. The vacuum only gauge at least has marks down to 2 inHg.
Did an 11 mile drive (the shortest out and back to any place of business around me) so the engine was well warmed up and then plugged the vacuum gauge on.
As expected, the engine idled rough while the dipstick was uncapped.

I measured 3 inHg. This remained unchanged when revving up and letting off, maybe dropping to 2.5 inHg when holding 2k rpm. But that was in park, so no real loading.
As the plug was just stuffed into the dipstick tube and not secured against popping out under road vibrations, I didn't risk driving with the combo gauge attached to see if it registered any movement under loaded driving.

I didn't have a boost tap on the intake to measure the intake manifold, but a prior experiment put that at around 18 inHg, with it bouncing between 16 and 20 with revving up and letting off (again, in park).

[old guy]

Nice work! That falls right in line with the 2.93 inHg listed for the EA888 Gen 3 engine.

I see that you have a 2009 2.0T. Are you running a black cap PCV?

[muffinman92]

Well an update

The code has come back on. I have spayed everything that I can down with carb cleaner to see if here is any leak, but nothing showed up. Car still drives fine until trying to build higher boost. It just kind of doesn't go anywhere even though the gauge is reading normal boost levels. Could I be throwing a P2187 code from a bad Diverter Valve? Any ideas what to check.

[Smac770]

I had the oil consumption fix done maybe 5 years ago, so I'm on a white cap.
Original black cap replaced by white cap during oil consumption fix, 83k miles.
Diaphragm torn, replaced by diaphragm in Dorman kit (only the diaphragm; use your original spring if at all possible), 126k miles.
Diaphragm torn, replaced the whole PCV with a new one (white cap again), 154k miles.
Still going now at 193k miles.

[old guy]

Well an update

The code has come back on. I have spayed everything that I can down with carb cleaner to see if here is any leak, but nothing showed up. Car still drives fine until trying to build higher boost. It just kind of doesn't go anywhere even though the gauge is reading normal boost levels. Could I be throwing a P2187 code from a bad Diverter Valve? Any ideas what to check.

Let me make sure that I am understanding correctly. Your boost gauge is reading normal boost levels but when you crank on it but you aren't getting the performance you have had in the past.

A few questions:

What boost levels are you getting under load? How are you reading the boost signal? Mechanical or electrical gauge? Where are you picking up your boost signal?

[muffinman92]

Let me make sure that I am understanding correctly. Your boost gauge is reading normal boost levels but when you crank on it but you aren't getting the performance you have had in the past.

A few questions:

What boost levels are you getting under load? How are you reading the boost signal? Mechanical or electrical gauge? Where are you picking up your boost signal?

THe boost gauge I have is a P3 gauge. I usually boost up to about 20-24lbs of PSI depending on the gear/RPM

[old guy]

THe boost gauge I have is a P3 gauge. I usually boost up to about 20-24lbs of PSI depending on the gear/RPM

Is it the P3 boost gauge that uses an actual boost signal or the P3 VIDI that uses the OBD port and reads from the MAP sensor?

EDIT: The reason I am asking this question is because the P3 boost gauge utilizes a boost tap from the intake manifold after the throttle body whereas the the P3 VIDI utilizes the signal from the MAP sensor that is in front of the throttle body. One is actual whereas the other is a calculated value. I don't know how significant that will be as I am struggling to think of a situation that would allow noticeably reduced performance while maintaining the same boost levels.

More information is always helpful in coming up with a possible diagnosis.

[Spawne32]

Well an update

The code has come back on. I have spayed everything that I can down with carb cleaner to see if here is any leak, but nothing showed up. Car still drives fine until trying to build higher boost. It just kind of doesn't go anywhere even though the gauge is reading normal boost levels. Could I be throwing a P2187 code from a bad Diverter Valve? Any ideas what to check.

Don't do that... its not going anywhere because its probably running insanely lean. You could have a legitimate problem with the cars fueling system so you need to look at the rail pressure on the high side of the fuel system and the duty cycle of the pump in the tank. I would also replace that o2 sensor if it has some miles on it. I have seen them fail lean or rich before.

[old guy]

If you have the Mityvac vacuum pump/gauge, the largest attachment piece fits into the dipstick hole just perfect.
The Mityvac combination (vacuum/pressure) pump/gauge lacks and scale markers between 5 inHg vacuum and 2 psi pressure, just calling it all zero. The vacuum only gauge at least has marks down to 2 inHg.
Did an 11 mile drive (the shortest out and back to any place of business around me) so the engine was well warmed up and then plugged the vacuum gauge on.
As expected, the engine idled rough while the dipstick was uncapped.

I measured 3 inHg. This remained unchanged when revving up and letting off, maybe dropping to 2.5 inHg when holding 2k rpm. But that was in park, so no real loading.
As the plug was just stuffed into the dipstick tube and not secured against popping out under road vibrations, I didn't risk driving with the combo gauge attached to see if it registered any movement under loaded driving.

I didn't have a boost tap on the intake to measure the intake manifold, but a prior experiment put that at around 18 inHg, with it bouncing between 16 and 20 with revving up and letting off (again, in park).

I used my Harbor Freight Vacuum gauge and checked vacuum at the dipstick tube at idle. It measured 2.5 inHg and dropped slightly when holding at 2k rpm. I have a fairly new OEM 06H103495AK PCV combi valve. My manifold vacuum at idle is 22 inHg.

[Peter.dupuis]

I ordered one of the indestructible pcv diaphrams that spawne posted the link to just to have an extra and the piece I received was the exact same oem piece already in the car, which wasn’t cracked or anything so good but still leaking air. Sounds like it’s barely hissing air out of the pcv just can’t pinpoint an exact location. I’ve had an ecs gift card sitting around so I decided to use it on a catch can kit so I can eliminate the pcv altogether. Hopefully that does the trick. P2187 and p2279 soft codes started popping up last week but I’ve heard air hissing out for a while now.


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[Dcferolino]

So when you remove the oil cap cover the car shakes and idles differently is normal?


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[old guy]

So when you remove the oil cap cover the car shakes and idles differently is normal?


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Yep. And if you want to check to see if your PCV combi valve is working properly go spend $14 at Harbor Freight. Clicky click® (https://www.harborfreight.com/Fuel-Pump-and-Vacuum-Tester-62637.html)

Pull out your oil dipstick (or dipstick plug if you don't have a dipstick), stick the rubber adapter into the hole and take a vacuum reading. It should be between 2→3 inHg.

[Dcferolino]

Yep. And if you want to check to see if your PCV combi valve is working properly go spend $14 at Harbor Freight. Clicky click[emoji768] (https://www.harborfreight.com/Fuel-Pump-and-Vacuum-Tester-62637.html)

Pull out your oil dipstick (or dipstick plug if you don't have a dipstick), stick the rubber adapter into the hole and take a vacuum reading. It should be between 2→3 inHg.

Just curious, because the car is bout to cut off or die out but when you try to put it back it sucks down really hard


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[old guy]

Just curious, because the car is bout to cut off or die out but when you try to put it back it sucks down really hard


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Get a vacuum gauge and check the amount of vacuum. If it's considerably more than 3 inHg then consider replacing your PCV valve.

[7786]

I just replaced a bad PCV yesterday and took some videos (diaphragm tore a couple years ago so I replaced it with the Dorman version, it only lasted 2 years so I replaced the entire the PCV this time). You can see the oil cap is pretty difficult to turn and pull off when the PCV is bad due to a strong suction. The good PCV still had a slight suction but the cap was very easy to take off. The engine idled rough with both versions when the oil cap is removed. Some symptoms I had was a slight shake at idle that would come and go, weak acceleration and oil residue forming around the oil cap.

Here is a before video:

https://youtu.be/qIABnKLFkxM

And here is an after:

https://youtu.be/H8FoOe8PydU

https://i.imgur.com/RyssrLp.jpg

[Slick_B8]

I just replaced a bad PCV yesterday and took some videos (diaphragm tore a couple years ago so I replaced it with the Dorman version, it only lasted 2 years so I replaced the entire the PCV this time). You can see the oil cap is pretty difficult to turn and pull off when the PCV is bad due to a strong suction. The good PCV still had a slight suction but the cap was very easy to take off. The engine idled rough with both versions when the oil cap is removed. Some symptoms I had was a slight shake at idle that would come and go, weak acceleration and oil residue forming around the oil cap.

Here is a before video:

https://youtu.be/qIABnKLFkxM

And here is an after:

https://youtu.be/H8FoOe8PydU

https://i.imgur.com/RyssrLp.jpg
I did the same thing with a dorman diaphragm. They’re absolutely hot garbage. Oreilly hated me because I would go in there every 1-2 months and get it replaced. Went through about 16 before I said fuck this lol did some research and saw these for sale. Same design being used in the new oem model pcv.
https://www.ebay.com/itm/RKX-2-0T-INDESTRUCTIBLE-PCV-valve-upgrade-for-VW-Audi-TFSI-MK6-MK7-B8-Volkswagen-/233114364631?_trksid=p2385738.m4383.l4275.c10

Also if you do decide to buy this one, make sure to reuse both spring and oem cap. Whether it was the dorman or this diaphragm, the cap that came with them ailowed air to come in. Other than that, no issues with this design so far and about 30k miles on mine

[the-quattro-man]

^ So this new upgraded and indestructible diaphragm is all you need to prevent your pcv valve from crapping out. No need to replace the whole thing, correct? I need to replace mine soon just as a preventive measure.

[old guy]

^ So this new upgraded and indestructible diaphragm is all you need to prevent your pcv valve from crapping out. No need to replace the whole thing, correct? I need to replace mine soon just as a preventive measure.

The diaphragm is the PRV (Pressure Regulating Valve) portion of the PCV combination valve. There are also several check valves in addition to the PCV combination valve. The PCV combi valve allows for metered air to move in both directions. There is also a built in oil/air separator. Failure of any of those components can cause significant problems.

Personal Opinion: Replace the entire valve every 50K miles with the latest OEM revision (AH for the black cap, AK for the white cap). Stick a spare diaphragm in the trunk to be covered if the diaphragm happens to fail while on the road.

[Peter.dupuis]

^ So this new upgraded and indestructible diaphragm is all you need to prevent your pcv valve from crapping out. No need to replace the whole thing, correct? I need to replace mine soon just as a preventive measure.

I have a 13 and it already had the upgraded diaphragm, looked good as new at 75k. The cap pops off pretty easily check it first


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[the-quattro-man]

I have a 13 and it already had the upgraded diaphragm, looked good as new at 75k. The cap pops off pretty easily check it first


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Ok thanks.

[the-quattro-man]

The diaphragm is the PRV (Pressure Regulating Valve) portion of the PCV combination valve. There are also several check valves in addition to the PCV combination valve. The PCV combi valve allows for metered air to move in both directions. There is also a built in oil/air separator. Failure of any of those components can cause significant problems.

Personal Opinion: Replace the entire valve every 50K miles with the latest OEM revision (AH for the black cap, AK for the white cap). Stick a spare diaphragm in the trunk to be covered if the diaphragm happens to fail while on the road.

That's what i thought as there are other components inside PCV that could also fail. I most likely will replace the whole unit. Replace the stock diaphragm with the upgraded one and keep the stock in the car as spare for emergency.

Tks.

[JLAllroad]

I used my Harbor Freight Vacuum gauge and checked vacuum at the dipstick tube at idle. It measured 2.5 inHg and dropped slightly when holding at 2k rpm. I have a fairly new OEM 06H103495AK PCV combi valve. My manifold vacuum at idle is 22 inHg.

I also have an AK, the original 68k, and hit between 19-22inHg at idle(warm) or in gear coasting with the AC on. This is measured on a P3 with analog sender with an ECS boost tap at the manifold.

2015 B8.5 Allroad. APRstg2. 5280elev, if it matters.


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[old guy]

I also have an AK, the original 68k, and hit between 19-22inHg at idle(warm) or in gear coasting with the AC on. This is measured on a P3 with analog sender with an ECS boost tap at the manifold.

2015 B8.5 Allroad. APRstg2. 5280elev, if it matters.




That's a nice healthy vacuum at idle! Now check your vacuum on the block to see if the PCV combi valve is functioning properly. You can even use your P3 gauge to check it. Simply unplug your manifold boost tap and plug it with anything. Fabricate a rubber plug to stick in your dipstick tube and hook it up to your P3 vacuum line. You should see between 2 to 3 inHg on the block.


https://i.postimg.cc/DwD7ZxTq/Boost-tap.jpg

[Spawne32]

Went to look at my PCV again....dealer I bought the car from put a vaico on there. -_-

[wilmar13]

I made this doc for another reason, but it seems it might be useful here.
I've never measured my crankcase vacuum at idle (the common process seems to be to tape the gauge tube to the dipstick opening), but I measured 18 inHg in the manifold using a boost tap on the PCV-manifold line. This seems normal; most what I found said ~20. I have not found any docs noting the expected normal vacuum in the crankcase at idle; only that the diaphragm valve is the protector of the crankcase from excessive vacuum at the intake manifold or turbo inlet that would impact the oil seals.

One reference I used was https://www.briskoda.net/forums/topic/442333-20-tsi-pcv-suction-from-tiny-hole

In this document was a diagram that showed a modification to the EA888 Gen2 PCV (which is different from the EA888 Gen1 in regards to the breather tube and high pressure bypass implementation) to add an additional valve between the cyclone separator input and the cylinder head galley. I would have assumed that the cylinder head galley was joined with the crankcase galley from a pressure perspective. Ie, the oil filler hole, am I not pouring oil into the cylinder head galley and then it just drains down? Or is the oil filler hole actually an isolated path down to the oil path? But so I'm not sure if that's there on which of the Gen1, the Gen2 black cap, the Gen2 white cap, or the Gen3 (looks like the Gen3 added a port for the EVAP connection to the manifold too, rather than a separate EVAP opening on the manifold).

The pic has what I expect are the valves in their idle positions. The manifold vacuum is pulling down on the diaphragm valve somewhat, but not entirely closed (is my expectation; again, lacking details in any SSPs; the pressure management is regulated by the strength of the spring, ie black cap vs white cap difference, at least one of the differences). This vacuum cascades through the fine oil separator and coarse oil separator to the crankcase, where it opens the breather valve to pull in fresh air from the turbo intake.

When the diaphragm tears, the atmospheric pressure backing the diaphragm is sucked out (I assume the small hole to outside ambient prevents the atmosphere from winning the tug of war with the manifold vacuum) and now there's no loading on the spring, so the diaphragm valve is pushed wide open. This passes far more of the manifold vacuum to the crankcase, and we get the sucked on oil cap issue. It's less clear why pulling the oil cap or dipstick cap smooths the idle in this scenario (with a working PCV, pulling the oil cap or dipstick cap will of course create a rough idle, same as when the PCV diaphragm is torn and letting outside air in that way). I've actually done that when my PCV had a torn diaphragm; covering the PCV vent hole smoothed out the idle, but so did leaving the PCV vent hole whistling and pulling the dipstick cap. Covering the PCV vent hole and pulling the dipstick cap restored the rough idle; though, that makes sense at this point.

137012
I am still trying to wrap my mind around exactly how everything should work and all the failure points, there is a lot of moving parts here. I am curious if anyone thinks the vacuum pump has a role to play, if it actually can move much volume of air when it has a leak on the vacuum side?

I have 2011 Q5 but this forum had most hits for technical stuff... I have had a problem with intermittent boost issues, and so I went in for first time and replaced N75 and diaphragm in PCV valve (has updated part and engine was rebuilt due to oil consumption). The old diaphram was fine, so not sure if that was the issue. While I was in there I discovered the major oil leak was from the port on the vacuum pump. I had the RKX vacuum pump reseal kit, but the connection to port was really loose and the o-ring on the connector was square (not o-ring). It didn't look like it had any other leaks and I didn't want to mess with removing it, but it got me thinking. The oil is because it is open to cam and there are a couple passage ways, but I really can't find much technical detail about the pump itself, but in order to create a vacuum for the brake booster, it has to displace into the crankcase... correct? Normally this would be negligible volume with no leaks, but if there is a leak like the port connection is loose, it would act to pressurize the crankcase. I don't know maybe it doesn't matter unless you have an intermittent leak, which needs to be fixed anyway. The fact that it was leaking oil indicates there is positive pressure anyway which points back to faulty PCV, how could it leak at vacuum port that should be creating vacuum at all times for brake booster???

As a perhaps unrelated anecdote but another reason I am trying to get my arms around the dance the systems play together, my oil filter was crazy tight. I had to stab it with two screwdrivers and use a 3' pry bar to loosen it and it tore the oil filter before finally breaking free. It was like 200ft lbs to loosen.

[Theiceman]

Inorrect...
Vacuum pump has zero to do with manifold vac. So put it out if your mind.
Vacuum pump is driven off intake cam and drives a pump for brake booster and evap leak testing only

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[wilmar13]

Inorrect...
Vacuum pump has zero to do with manifold vac. So put it out if your mind.
Vacuum pump is driven off intake cam and drives a pump for brake booster and evap leak testing only

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Its driven off exhaust cam, no? Its mounted behind exhaust cam at least. Its purpose is for brake booster and evap, but what happens when there is a leak at the port? Its a pump so it has to have an input and output. As a vacuum pump its intake is a closed system until you have a leak, then it seems like now it can actually move air. IDK, I realize it would have negligible effect to crank pressure, but I am trying to understand how oil is leaking out something that should be creating vacuum. I would like to see more detail about how the pump functions, like how it actually creates vacuum. I can't find anything in the SSP or on the parts diagrams.

[wilmar13]

Yeah, OK look up the supplier and then voila you find how the part works, haha. Pierburg has a really good 3d rendering of how the single vane mechanical pump works, and yeah if you look at 1min10sec it shows it will displace into the crank through a check flap if you have a leak like I did. I doubt it flows enough volume to effect crankcase pressure, but I see how it can leak now.

https://youtu.be/mp3NeWuEDk8

[Theiceman]

Oh sorry yes . Thought I was on b7 forum as I have one of those too. . Same principle though.
The pump is designed to be independent of manifold vacuum. So you don't lose vacuum when turbo kicks in.

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[silver_tt]

Some more visuals to go with the explanation:

These excerpts from the 2.0L 4V TFSI Study Guide explain the function of the PCV portion of the Crankcase Ventilation System.

https://i.postimg.cc/VsntpYmX/PCV-definition.jpg

This picture shows the location of the PCV combination valve in the Crankcase Ventilation System. It can flow air in two directions. When the intake manifold is under vacuum the PCV combination valve allows filtered, metered purge air to be drawn through the connection at the turbo inlet. This purge air enters the block and is then pulled out through the Crankcase Ventilation System into the intake manifold. The amount of negative pressure is being controlled by the Pressure Regulating Valve (large diaphragm).

When the block pressure exceeds the spring pressure in the PCV combi valve it will then open up and allow air to move in the opposite direction toward the turbo inlet to reduce the block blow-by pressure. Manifold pressure is blocked by the two non-return valves.
https://i.postimg.cc/vm5MMSB2/PCV-Valve.jpg

Sorry to revive an old post. I am trying to complete my understanding of the "PCV Combination Valve". I recently replaced my PCV preemptively (I do it every 40-50K miles just as you suggested in another post so we agree). In doing so I found a failure of the PCV combination valve in that it was not seated properly (see picture 1) and when I pulled the hose that leads to the turbo inlet it had a a lot of oil in the line (I would expect some blow-by but not as much oil as spilled out). Which leads me to my main question. I had initially assumed that the PCV combination valve only opens under boost when positive pressure causes that little red/orange button (see picture 2) to move up and allowing air-flow/blow-by to move toward the turbo inlet in charging mode. BUT clearly the diagram from the 2.0L 4V TFSI Study Guide shows that the air can also move the other direction when under NA mode from the turbo inlet and into the head that the PCV sits on top of (the 3 light green arrows). So the question is how does the air move in that direction? Is it the little hole in the red button that allows the air to move that way? I replaced the part and took pictures of it but it's now on my car so I can't study it further.

Also looks like you answered your questions on crankcase vacuum but as part of Audi's "solution" to the oil consumption problems they bumped up the vacuum from ~4-6" H20 to ~35" H20 (see picture 3) to help ring seal and fuel dilution which is a major consideration with respect to DFI engines.

223297223296223298

[old guy]

The PCV combi valve is a spring loaded valve that will open when the block pressure gets to around 2.5 psi. As you have noticed the combi valve also has a flapper valve incorporated into the unit. That would be the orange disc in your pictures. If you gently pry up the flapper valve you will notice a small hole underneath the flapper.

When the block is under vacuum the purge air gets pulled from the TIP connection, through the flapper valve and into the block and ultimately exiting through the PRV and into the intake manifold.

I'm not sure what the units are in the third pic you posted. The vacuum spec is ~ 3in Hg for the white top (AK version) and a bit less for the original black top versions.

[Smac770]

The specs are 20 mbar (black cap) and 100 mbar (white cap), which translate roughly to .6 inHg and 3 inHg. Or in your case, 8 inH₂O and 40 inH₂O.

[silver_tt]

Thanks for the information. Yes, I was familiar with the spring loaded valve functionality of the combi valve. But if I understand you correctly you are saying that the red rubber seated in that orange disc is a flapper valve and if I still had the part in my hands I could gently peel up that red rubber. That explains it, thank you very much. As Smac noted, my units are in " of H20 (Mbar, " Hg, etc there are many measures that you can easily convert between or my device will measure any of those units directly as well). Also smac, yes, I agree with your PCV specs both from before and after Audi bumped up the crankcase vacuum. Thank you.

[Smac770]

Well, they're not "my" specs, per se. They are straight from Audi documents related to the PCV change.

[silver_tt]

I understand -- it's documented in ETKA that the new PCV is 100 mbar vacuum spec so there's really no disputing it or ownership of that fact

[old guy]

But if I understand you correctly you are saying that the red rubber seated in that orange disc is a flapper valve and if I still had the part in my hands I could gently peel up that red rubber.

https://i.postimg.cc/7ZBKkzsY/IMG-0550.jpg

[silver_tt]

Old guy you are awesome, thank you for this outstanding information! You may be old, but you're smart too. :) Crazy how much functionality is built into this PCV, much more so than originally meets the eye.

[plinski]

Hello to all,

Probably i have problem with PCV, i see oil in Blow-By Line to intake manifold same and in exaust line to turbine inlet, and i have big consumation of oil, around 1 liter per 500 km, today i analyse PCV and i see that when i put air from blow by line to exaust, air go to blow by line manifold, in scheme i see that between this 2 line have non return valve, do you mean that this valve is broken? ( i cant see this valve with eye because they is inside )

In this moment i have PCV model AE.

244288

thanks

[2stroke]

PCV-system

I have a TSI ( EA888 , Gen-2 ) engine.
According to the sticker on the engine it's been built ---> 2011-09-11

What part #'s are the best and the latest updates I can look for ? [confused]
And what parts in the PCV system should I change ? [confused]

( I do not want to put a oil catch tank )

[Smac770]

Look at your engine. Does the PCV have a black cap or white cap? Replace it with the current version of whichever cap you have: 06H 103 495 AH for black or 06H 103 495 AK for white.

Notice the white cap: https://parts.audiusa.com/p/Audi__/Engine-Crankcase-Vent-Valve/67824620/06H103495AK.html

[JLAllroad]

Look at your engine. Does the PCV have a black cap or white cap? Replace it with the current version of whichever cap you have: 06H 103 495 AH for black or 06H 103 495 AK for white.

Notice the white cap: https://parts.audiusa.com/p/Audi__/Engine-Crankcase-Vent-Valve/67824620/06H103495AK.html

This assumes that the PCV hasn’t been changed before. I often find, on used vehicles, that you cannot always go by the PCV that is in the car.


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[2stroke]

Look at your engine.
Does the PCV have a black cap or white cap ?
Replace it with the current version of whichever cap you have: 06H 103 495 AH for black or 06H 103 495 AK for white.
This assumes that the PCV hasn’t been changed before.
I often find, on used vehicles, that you cannot always go by the PCV that is in the car. VAG part #'s

# 06H 103 495 E
# 06H 103 495 AD
# 06H 103 495 AE
# 06H 103 495 AH
# 06H 103 495 AK

Are there more part #'s for the complete PCV valve ?
Does anyone know what the differences are ?

Are there more parts in the whole PCV system that should be replaced ?

[Theiceman]

There are two types of PCV.. we are not talking about rev.
Even vin wontt tell you as there was a patch that changed it on some cars.
Heed smacs advice and first determine which one you have currently.
Best place to start..

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[Smac770]

There's two PCVs, black cap and white cap. You don't care about outdated revisions. There is only AH and AK for new purchases.

If you are not the original owner or have some reason to wonder about the validity of the PCV physically on the engine, your only option is to review the installed ECM software rev and determine from there which you should be using.

https://www.audizine.com/forum/showthread.php/902214-Stutter-rough-idle-when-first-starting-car-and-clears-up-after-3-4-seconds?p=14258030&viewfull=1#post14258030

Those are for US spec CAEB engines. I would imagine the values from an EU CDNC engine will be different.

The parts catalog says the change from black cap to white cap was made Mar 31, '12. So if they don't do the oil consumption stage 1 stuff there, you should still be running a black cap.

[2stroke]

There are two types of PCV.
We are not talking about revisions.
Even Vin # won't tell you as there was a patch that changed it on some cars.
Heed Smacs770 advice and first determine which one you have currently.
Best place to start.
There's two PCVs, BLACK cap and WHITE cap.
You don't care about outdated revisions.
There is only AH and AK for new purchases.

If you are not the original owner or have some reason to wonder about the validity of the PCV physically on the engine,
your only option is to review the installed ECM software rev and determine from there which you should be using.

https://www.audizine.com/forum/showthread.php/902214-Stutter-rough-idle-when-first-starting-car-and-clears-up-after-3-4-seconds?p=14258030&viewfull=1#post14258030

Those are for US spec engines.
I would imagine the values for EU spec engines will be different.

The parts catalog says the change from BLACK cap to WHITE cap was made ----> 2012-03-31
So if they don't do the oil consumption stage 1 stuff there, you should still be running a black cap. My engine build date: 2011-09-11

I have the all BLACK version # 06H 103 495 E

I'm the second owner of the car.

How to determine the installed ECM software ?
( I have my own VCDS )

What PCV type and part # should I order ?

248527

[Theiceman]

smac told you exactly what to order and you even quoted it ..

06H 103 495 AH for black

[Smac770]

Rev E, that's probably the original for a late '11 build. E was dropped for purchase at the start of Mar '14.

As for reading the ECM software revision, you'd need a tool like VCDS or OBDeleven. If you have VCDS, just look at the lines for the ECM in a scan:


Address 01: Engine (DL0MA-CAEB) Labels:| 06H-907-115-CAB.clb
Part No SW: 8K2 907 115 AL HW: 8K2 907 115 D
Component: 2.0l R4/4V TF H14 0001
Revision: E1H14--- CVN: CC36E0B0

[2stroke]

Smac770 told you exactly what to order: # 06H 103 495 AH for BLACK. [up]


Rev E, that's probably the original for a late '11 build.
E was dropped for purchase at the start of Mar '14.

As for reading the ECM software revision, you'd need a tool like VCDS or OBDeleven.
If you have VCDS, just look at the lines for the ECM in a scan
Engine code: CDAA

-------------------------------------------------------------------------------
Address 01: Engine (CDA) Labels:. 06J-907-115-CDA.clb
Part No SW: 3T0 907 115 G HW: 1Z0 907 115 F
Component: 1.8l R4/4V TFSI 0030
Revision: AAH18--- Serial number:
Coding: 0203000C180F0160
Shop #: WSC 73430 790 00083
VCID: 353726C2C9431DC36C5-8060

No fault code found.
Readiness: 0000 0000

-------------------------------------------------------------------------------

[Smac770]

CDAA? This is an A3 or TT with a 118kW transverse 1.8T EA888 Gen2 engine? Definitely not a 155kW longitudinal 2.0T EA888 Gen2 CDNC like would be in an A4.

But the PCV unit is still the same on the CDAA as on the B8.0 CDNC/CAEB. Originally 06H 103 495 E, now 06H 103 495 AH.

[2stroke]

CDAA ?
This is an A3 or TT with a 118 kW transverse 1.8 TSI EA888 Gen2 engine ?
( Definitely not a 155 kW longitudinal 2.0 TSI EA888 Gen2 CDNC like would be in an A4. )
But the PCV unit is still the same on the CDAA as on the B8.0 CDNC/CAEB.
Originally 06H 103 495 E, now 06H 103 495 AH. Yes, 1.8 TSI EA888 Gen2 118 kw.
The 1.8 TSI EA888 Gen2 engine is exactly the same as the 2.0 TSI EA888 Gen2 engine.
Only the displacement differs.

( Over here in Europe the A4 "B8" was sold both with 1.8 TSI and 2.0 TSI EA888 Gen2 engines )

[Smac770]

Odd that VCDS would call it a CDAA engine. CDAA is a 118kW transverse 1.8T engine. The 118kW longitudinal 1.8T in an A4 would be a CABB or CDHB engine; I imagine CDHB for an '11 build. What are the letters on the sticker on the upper timing cover on the front of the engine?

[2stroke]

What are the letters on the sticker on the upper timing cover on the front of the engine ? Are there any more details / parts in the PCV system that I should also change ? [confused]

248883

[Smac770]

Not normally. There's the hose that goes from the PCV to the intake manifold and from the PCV to the turbo. If either of those were having an issue, you'd replace it. But I don't see a need unless you had identified some kind of leak or poor seal.

There is also the coarse oil separator down the left side of the block. That's the first object that crankcase vapors pass through before moving up to the fine oil separator, aka the PCV unit.

So I'd just replace the PCV and leave it at that unless there's specific releated issues you're tracking.

[Smac770]

Odd. I wonder if someone swapped that engine in and did the necessary to convert from trans to long. That's a *really* clean sticker. Like it has 0 miles on it. The CDAA was used in the A3 and TT, not the A4, because it's not turned the right way. Well, if it runs, ....