Pcv valve bad?

[Aaron5280]

Hey guys so I've been dealing with a pretty bad consumption issue with my 2012 a4 and was reading it could be pcv related. So I did the oil cap test and when I pulled the oil cap off my car didn't studder or stall it basically stayed the same. Does this mean my pcv is bad? Im under the impression that if I remove the oil cap while it's running that it's supposed to make it idle rough but I noticed no difference. Does anyone know if I'm on the right track here?

[Allowencer]

Shouldn't affect idle at all. You should have some vacuum at the cap too, but I believe at idle PCV doesn't operate at 100%.

Do you have an all black PCV or one that has a white circle cap on it?

One way to tell if it's working properly is to get a mechanical vacuum gauge on your oil dipstick and check vacuum.

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[Smac770]

If you have the white cap, yes, removing the oil fill cap should definitely make the idle rough. It does on mine. If you have the black cap, no idea. With it's much lower crankcase vacuum, it might not create as much an issue.

The accurate process is to use a vacuum gauge on the dipstick tube and actually measure the crankcase vacuum. 20 mbar (0.6 inHg) for black cap, 100 mbar (3.0 inHg) for white cap.

But the assessment of the PCV depends on the issue. If it's negative fuel trim or intake leak code or such, pulling the oil cap just confirms there's a leak in the engine that's already passing outside air to the intake manifold at idle. Nothing to do with having excess crankcase vacuum due to a torn diaphragm causing excessive scavenging.

If the engine hasn't had the pistons/rings replaced yet, you're probably simply facing that reality finally.

[Aaron5280]

The round part on mine is black but on the end square part it's white. It looks like this one
https://www.ecstuning.com/b-hamburg-...IaAhWpEALw_wcB

[Aaron5280]

I also don't have any codes and when I pulled the cap off it felt more like the air was pushing the cap into my hand rather than sucking it in

[Smac770]

The "cap" reference is to the rectangular part, not the round cap on the regulator valve, which is always black. So you have a "white cap".

Get a vacuum gauge and eliminate any of the "maybe, possibly, could be" vagueness. Get a factual measurement.

[Aaron5280]

Ok there has been a few times when driving my car kinda hard the breather hose has blown right off of the pcv valve and I would only notice when I would come to a stop my car would be barely idleing. Have you ever had this happen or could this be because there's extra pressure built up in there from a bad pcv causing it to blow the hose off?

[old guy]

Definitely replace the PCV as soon as possibly. Driving with the crankcase under pressure will play havoc with all of your oil seals. Especially the rear main oil seal (expensive replacement).

[Theiceman]

oh yeah the pic you showed is the white cap .. likely a check valve is plugged in the PCV. should really stumble when you remove the oil cap as you are creating a massive vac leak via the PCV.. back into the intake

[Aaron5280]

do you guys know if the PCV valve in the link that I posted is the correct one for my car? I’ve read on here that there’s different ones and that some PCVs require a software update from Audi. I just wanna make sure I get the exact same one that I have on their currently. I have a 2012 A4 Quattro 2.0 T. Engine code is CAEB.

[MongoMcG]

To know if you need the newer PCV - provide your VIN to an Audi dealer and ask if the phase 1 oil consumption fix was done. This includes a new front seal, the newer PCV and a software update. If you have the service history of the car you might find it on a work order, too.

When swapping the PCV pay attention to order of tightening and torque specs as laid out in the factory service manual. The spec is 11 Nm. A small torque wrench (like the kind they sell for bicycle work) is handy for work on the 2.0T and its myriad lower torque bolts - some as low as 1.5 Nm.

Note: In the FSM the PCV is referred to as an oil separator - more specifically, the "Oil Separator on Cylinder Head Cover".
Refer to ⇒ Servicing – 4-Cylinder 1.8L; 2.0L 4V TFSI Engine; Rep. Gr. 17; Crankcase Ventilation; Oil Separator, Removing and Installing. That is section 3.2.2 of the service manual.

[Aaron5280]

If the phase 1 oil consumption wasn’t done do I just get the same PCV that’s currently on it? And is the phase 1consumption with new PCV and software something that would’ve been done under warranty by the previous owner I’m sure any warranty on mine is well expired by now.

- - - Updated - - -

Sorry if these are stupid questions I’m still pretty new to all this

[DrGER]

do you guys know if the PCV valve in the link that I posted is the correct one for my car? I’ve read on here that there’s different ones and that some PCVs require a software update from Audi. I just wanna make sure I get the exact same one that I have on their currently. I have a 2012 A4 Quattro 2.0 T. Engine code is CAEB.

As noted by MongoMcG, that depends on the service history.
CAEB engines got the "black" PCV 06H103495AH through March 2012 build dates; after March 2012, "white" PCV 06H103495AK is fitted. But if the CAEB had the Stage 1 oil consumption fix noted by MongoMcG, the engine will now have the "white" PCV.

If you have access to VCDS or equivalent VAG diagnostic tool, post information from Address 01-Engine, for example:

Address 01: Engine (0-----CAEB)       Labels: 06H-907-115-CAB.clb
   Part No SW: 8K2 907 115 AG    HW: 8K2 907 115 D
   Component: 2.0l R4/4V TF H17 0002  
   Revision: E1H17---    
   Coding: 0114010A290F0160
   Shop #: WSC 99999 1023 2097151
   ASAM Dataset: EV_ECM20TFS0118K2907115AG 001002

and

Address 01: Engine (0-----CAEB)       Labels:| 06H-907-115-CAB.clb
   Part No SW: 8K2 907 115 AG    HW: 8K2 907 115 D
   Component: 2.0l R4/4V TF H20 0002  
   Revision: E1H20---    
   Coding: 0104010A290F0160
   Shop #: WSC 06208 000 00000
   ASAM Dataset: EV_ECM20TFS0118K2907115AG 001002

and described in this TSB: https://static.nhtsa.gov/odi/tsbs/20...21301-9999.pdf --g

[MongoMcG]

As noted by MongoMcG, that depends on the service history.
CAEB engines got the "black" PCV 06H103495AH through March 2012 build dates; after March 2012, "white" PCV 06H103495AK is fitted. But if the CAEB had the Stage 1 oil consumption fix noted by MongoMcG, the engine will now have the "white" PCV. --g

You can find the build date of your car in two locations - 1) the owners manual: inside the cover there should be a decal containing data such as engine/transmission and other option codes, build date, etc.. 2) a similar decal is stuck on the side of the spare tire compartment in the trunk.

There is a major difference in crankcase pressure between the two versions of the PCV. The later version was supposed to help hold the piston rings closer to the cylinder wall. It got customers out of the service bay long enough for the warranty to expire so the dealer/VW would not have to pay for replacing the pistons and rings under warranty, or so it seems.

The white cap PCV is the newer version. Since you have one installed then one could assume your build date is post-update or that the phase 1 work was done. But we know what happens when we assume things.

[Theiceman]

just look at part number on your PCV , order same number ...

[Aaron5280]

Is this the info

[Smac770]

An MY12 is already going to be running white cap from the factory.

Is that OBDeleven? So many screen caps. And I can't even copy the text string. But we see 8K2...AG 0004, so you're already past the sw rev that institutes the 100 mbar change.

So put a new AK on there, see what happens.

[Aaron5280]

Ak being the white cap?

[Theiceman]

yes

[Aaron5280]

The only part number on my pcv is v10-3320 and another set of numbers below that are 987073115

[DrGER]

The only part number on my pcv is v10-3320 and another set of numbers below that are 987073115

Hmmm, the OE part made by Hengst is well marked:

--g

[Smac770]

V10-3320 is the Vaico unit.

You can't go wrong with the Audi OE unit, but that's not cheap. I'd recommend the Hengst OEM unit over the Vaico third-party unit.
https://www.ecstuning.com/b-hengst-p...h103495ak~hen/

[Aaron5280]

Oriellys has a URO brand AK do you think that'll be ok to use until I can order a better one? I'm also wondering why there is a vaico unit on there, if audi did the stage 1 oil consumption I would think they'd put a oem one on. Also makes me wonder if my car is supposed to have a black top and someone just put the white one on not knowing or would my car even be running if the white top was installed without the new software?

[Aaron5280]

This is the one at oriellys

[Aaron5280]

this is the info that’s in the trunk compartment. It doesn’t show anything about a manufacturing date. and the second photo is the Carfax and the very first date that appears on it is March 3, 2012

[JLAllroad]

This is the one at oriellys

Based on what you have said your PCV is bad….that said I would not expect it to fix your consumption issues.

Do not get a cheap aftermarket PCV, as was already said get a Hengst which is essentially OE Audi.


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[MongoMcG]

Dag nabbit. Sorry. I sure thought the assembly date was there. But the Carfax date for shipping to the dealer is close enough. As for why there is a Vaico currently installed? The PCV/oil separator is a known failure point and seemingly always one of the first to be replaced, so it's no surprise to see the Vaico. The good Dr says old version was used through March 2012, but the TSB (updated as late as 2013) does not include any MY 2012's and Iceman says all 12's have updated version. Both guys are pretty smart, and I'm not, so ??

[DrGER]

... Also makes me wonder if my car is supposed to have a black top and someone just put the white one on not knowing or would my car even be running if the white top was installed without the new software?

The ECU software part number 8K2907115AG tells us the white PCV is correct. Who knows how the after-market PCV got installed along the way ? If you plan on keeping the car, get the OE part made by Hengst. --g

[Smac770]

The mo/yr of manufacture is not on the vehicle identification sticker placed in the spare wheel well during manufacturing.
The mo/yr of manufacture is on the vehicle identification sticker placed in the maintenance/owners manual during delivery.
It is also present on the VIN regulatory sticker. Driver's door jam for the US, right strut tower for the UK, etc.

The currently installed ECM software says have a white cap. History is not really useful at this point.

You still have no factual vacuum/pressure measurements to really drive choice validation. But if the PCV is so jacked up, then putting anything feigning competence on would be an improvement. But that uRO will be good for about as long as the price would imply, I'd expect.

[Theiceman]

how these usually go down ...

My car is starting to consume a ton of oil ... i read on the internet the cheapest thing to try is the PCV .. PCV is how much ?? forget it give me the knock off viaco version....

fe w weeks later . now i have another problem ? and I still have the Oil problem , it costs how much to replace pistons and rings ? ?

F#ck it , trade it in .... off to auction after trade in .... used car dealer buys it, washes it , sits it on the lot .. and it waits......

[Aaron5280]

Hey guys I ended up replacing the pcv yesterday and wanted to give you all a update as to what happened. First of all I really appreciate everyones input and advice on here and wanted to thank you guys for taking the time to answer all my questions even the dumb ones lol. Ok so I started looking into a pcv replacement because of oil consumption issues. Im sure I'll end up having to do pistons and rings in the near future but I heard the pcv is a good ace to start to hopefully slow it down or the the excessive crankcase pressure could be causing the oil to seep out of gaskets. When I was researching videos I saw that most people would take the oil cap off while the car is running and there would be some vaccum and that the engine would stumble and idle rough with the cap removed. I was led to believe that this is normal when the PCV is working correctly as you are creating a huge vacuum leak. So I did the test on my car and when I removed my oil cap it seemed absolutely nothing would change the car will still idle the same. there was almost no difference between having the cap removed or not. My car wasn't idleing rough in the first place, in fact it was idleing pretty smooth. I was expecting it to get rough without the cap but when I didn't I thought something must be wrong. I had no lean codes but I did have a code for to rich at idle bank one. Not sure if this is pcv related? Anyways after talking to you guys yesterday I went ahead and replaced the pcv with another AK white cap. The only one I could find in my town was the URO brand at oriellys so I picked it up. I figured a cheap functioning one is better than the broken one I currently had on until I can get a OEM replacement shipped to me when I took the old one off there is a little round piece of rubber. I believe it was orange on the underside of the PCV on the new one if you push on it it’s got a spring behind it, that little piece of rubber had completely fallen off of the PCV valve was sitting on top of the motor when I took it off.so I replaced the pcv with the new one and it started right up. I did the oil cap test and sure enough I had vacuum and my car would stumble and idle rough with the cap removed, it seems that it’s idling a lot smoother now and running a lot better. I didn’t realize how shitty my car was actually running. In the first few minutes after the start up I did notice a pretty loud ticking sound that wasn’t there before. Not sure this is normal, but I think it’s gone away now , I only drove a few miles but I’ll see if the noise is still there later today and let you guys know but it definitely is better and my previous one was definitely broken.

[Theiceman]

check valve failed.. as suspected from a Vaico part..

[Aaron5280]

yeah, I’m really glad I replaced it. I just couldn’t find anywhere online where someone was having the same symptoms as me such as removing oil cap and idle remaining the same and the idle really not being rough at all in the first place. I cleared my to riche at idle bank 1 code. I’ll have to wait to see if it comes back, but do you know if that was possibly related to the PCV?

[Theiceman]

yeah, I’m really glad I replaced it. I just couldn’t find anywhere online where someone was having the same symptoms as me such as removing oil cap and idle remaining the same and the idle really not being rough at all in the first place. I cleared my to riche at idle bank 1 code. I’ll have to wait to see if it comes back, but do you know if that was possibly related to the PCV?

its hard to say , Air/fuel and emissions management is a tricky business.. just drive it and see what happens.