Gripe about Oil Catch Can video

[BOPOH]

Hey everyone,

I bet most of you considered some sort of oil catch can setup and did some research about it, I'm doing it right now and came across the video at the bottom. Either I don't understand or this guy is completely wrong - unless i'm missing some vital information.

From what I understand from this video (keep in mind English is my 2nd language) this guy is saying:
1. Passenger side cam port is to INTRODUCE fresh air to the engine
2. by connecting it to INTAKE TUBE
3. Driver side cam port is to egress oily vapors to catch can

Sounds logical, but not if you study this 3.0T engine and that's where I get really confused(forgive me if I was mis-informed) based on the picture below:
1. Both cam ports are for egress oily vapors - not just driver side
2. Intake tube would create suction, especially under WOT - which will pull oily vapors in front of throttle body (according to video) and completely defeats the purpose of this entire system or possible damage supercharger with incompressible oil(exaggeration)


What's what?

[tenspeed]

I had the same initial thoughts when this thread was made on AW. It made me curious about how bad carbon build up was on the 3.0L engine. The vendor in this thread plumbed it the same way.

https://www.audiworld.com/forums/a6-...gines-2909914/

[BOPOH]

I've read numerous threads about valve coking, especially posts from GDI Tech. I'm OK about understanding this problem and here is what I took from all my reading so far:

1. To prevent build up of that tar on intake valves I need to introduce only clean air
2. PCV system is my enemy in this fight because it recirculates blow by gasses oil vapors and other junk that's going on inside the engine by spitting it on intake valves

my idea is to move PCV system recirculation outside the engine (oil catch can/air vaping system) and supply engine with only clean air - judging by this video, guy is completely clueless how PCV system is set up in 3.0T (unless i'm mistaken). If you look at the part number (06E103217AD or 06E103217AF) and diagram of the tube (SINGLE TUBE) which he refers to, makes no sense to me because both ends are designed to suck oil vapors into "Oil Separator Module"

[tenspeed]

I've read numerous threads about valve coking, especially posts from GDI Tech. I'm OK about understanding this problem and here is what I took from all my reading so far:

1. To prevent build up of that tar on intake valves I need to introduce only clean air
2. PCV system is my enemy in this fight because it recirculates blow by gasses oil vapors and other junk that's going on inside the engine by spitting it on intake valves

my idea is to move PCV system recirculation outside the engine (oil catch can/air vaping system) and supply engine with only clean air - judging by this video, guy is completely clueless how PCV system is set up in 3.0T (unless i'm mistaken). If you look at the part number (06E103217AD or 06E103217AF) and diagram of the tube (SINGLE TUBE) which he refers to, makes no sense to me because both ends are designed to suck oil vapors into "Oil Separator Module"

The passenger side leg is blocked off using TDI's installation. The drivers side has all the vacuum to suck the oil vapors.

It seemed to me that the AW thread ended up being a three page ad to sell that system and catch cans. I'm not buying that it cures 90-95% of the coking problem. With the unadulterated engine, how does fresh air enter the engine?

How about two catch cans? One on each side of the engine in series with the OEM tubing.

[BOPOH]

Ok maybe something like this - super fast drawing (about to go home from work)

1. PCV oil vapors egress to exhaust to pull it out with check valve like in this post (CLICK HERE)

2. Fresh air suction caused by supercharger to come from Air Filter(vented oil catch can - accidently just for show, should've been just air filter)

IGNORE "BLOCK this"

basically, oily vapors from both cams ports go to exhaust while existing port at oil separator module sucking air will be supplied by fresh air from separate air filter

more simplification - no other systems or air flows are touch in this set up, only above mention tube part number 06E103217AD or 06E103217AF is separated from the engine itself


PCV delete.jpg


THIS IS NOT COMPLETE BY ANY MEANS - just brain storming!!!!

[BOPOH]

more info from this thread, especially post with picture of cylinder head

[tenspeed]

This makes sense to me. It could be the root/major cause of the carbon build up. I'll be reading more of the thread.

Post #84 on page three
http://www.audizine.com/forum/showth...=1#post9887102

"From the latest updates I have received, recirculating carbon species from both the crankcase breather and combustion process are only minor contributory factors. Testing has proved that the primary source is from the valve stem seals. The actual cause of the build-up is interesting but not surprising.

The efficacy of water/methanol injection is very limited because the build-up is primarily composed of very hard and chemically active long-chain carbons (engine oil), which create VERY hard layers of carbonaceous build-up.

I am in the fuel and oil modification business and have been working with numerous parties on this issue for a number of years now. I have written an article on this revealing to exact reason but I am awaiting permission before I can publish it."

edit: I was reading and trying to understand the thread for 3-4 hours. Some very interesting stuff from AndyUK around mid-2014. He summarizes in post #160

"FACT 1: The majority of the build-up is oil from the valve stem lubrication process. This is the first common
denominator and has been known for some time.

FACT 2: The oil is catalysing with the valve because of the nickel and chrome alloys used to harden the valve.
This is the second common denominator and the ROOT CAUSE unforeseen by the manufacturer.

FACT 3: Due to a number of factors that I can’t detail now, the carbon remains chemically active to such a
degree that it becomes a “magnet” for ALL CARBON SPECIES.
This provides us with very valuable information such as WHY the oil bonds so readily (FACT 2) and WHY it won’t
self-manage (FACT 3). Are there other factors? Of course, but the fact remains that all TFSI engines suffer from
build-up. We also know that NA engines are worse off etc., etc. The main variable is mileage."

He mentions using the 502 and 505 types of oil. He wouldn't mention a brand because he's in the business and blends change rapidly and they are different for different areas. He uses a blend in his car.

So there's a guy selling catch can systems that says it will stop 90% of the build up and a researcher in the UK that says that the oil is coming from the valve stem lubrication process. My brain hurts...

[ntsantos]

ECS just came out with a complete kit for the B8S4, but should work with the C7. A little pricey at $300, but it's complete.

Sent from my K88 using Tapatalk

[audi bug]

I think catch can is waste of money and effort:
1. Most of catch can set-ups are wrong as you saw in the video. Catch can outlet is routed back to the PCV system, and you never know true effect of catch can vs factory PCV system.
What catch can is catching is oil in raw crank case vapor not the oil in the vapor after the PCV system. What I am saying is that amount of oil caught in the catch can is not true measure of oil that is dumped into intake.
I will believe the effect of catch can if it is set up between the factory PCV and the intake. That will be a challenge to take care boost from super charger.
Using passenger side valve cover as fresh air inlet is wrong thing to do. Fresh air will go through the labyrinth passage in the valve cover in reverse direction of design intent (which supposed be the first oil separator before the
PCV) and will pick up oil mist in valve cover and cylinder head. The thin tube labelled "PCV line with non return valve" in your first picture is the fresh air supply to the crank case.
2. There is very little oil consumption for 3.0L TFSI indicating very low oil loss due to vaporization. KNOCK ON WOOD!
3. I reviewed your pictures of intake valves (btw, thanks for sharing them) and saw a few valve stems that had unusual lumps of carbon deposit compared to the face of the valve.
That indicates to me that deposit was due to oil from valve stem (sleeve) not from the oil vapor from PCV system. Exhaust valves don't suffer this carbon deposit because exhaust valve operating temperature is high enough to burn them off. Carbon deposit occurs on lower operating temperature condition like light throttle stratified combustion.

addition:
4. This paper showed that completely eliminating blow by gas had no impact on intake valve deposit (IVD, see page 14).
http://www.pecj.or.jp/japanese/overs...rence12-19.pdf
The paper has study on base oil type and used oil for IVD although it didn't define the age of used oil.

[BOPOH]

a researcher in the UK that says that the oil is coming from the valve stem lubrication process. My brain hurts...

3. I reviewed your pictures of intake valves (btw, thanks for sharing them) and saw a few valve stems that had unusual lumps of carbon deposit compared to the face of the valve.
That indicates to me that deposit was due to oil from valve stem (sleeve) not from the oil vapor from PCV system. Exhaust valves don't suffer this carbon deposit because exhaust valve operating temperature is high enough to burn them off. Carbon deposit occurs on lower operating temperature condition like light throttle stratified combustion.

Good point guys! I totally forgot about valve stem seeping oil, which I believe is part two of this issue. Unfortunately other than using good oil at this point there is no solution, unless there is new design for valve stem seals - any updated versions?

I'm not considering oil catch can at all, only clean air in and dirty venting to atmosphere through filter.

The thin tube labelled "PCV line with non return valve" in your first picture is the fresh air supply to the crank case.

I dont believe it's fresh air supply, i think it's passive vacuum. There are two stages for PCV (WOT and idle), this thin tube is for idle vacuum which would be totally insufficient under WOT. Cam cover tubes will suffice this purpose.

That being said, I believe fresh air to crankcase ventilation is coming from right side of "oil separator module"





Here is my train of thought, those suctions tubes that go into left/bottom inlet of "oil separator module" are pretty big plus supercharger also has a hole sucking air from that module. To compensate such a big demand of vacuum, fresh air should have at least similar size pipes. That's why I believe right side/top of module is fresh air inlet to crankcase directly, so it can later mix with oil vapors and blow by gasses and other junk that oil is designed to clean.

Am I on the right path of thinking? If anybody have technical data or manuals, that would be great if I can study them

[audi bug]

I'm not considering oil catch can at all, only clean air in and dirty venting to atmosphere through filter.

I dont believe it's fresh air supply, i think it's passive vacuum. There are two stages for PCV (WOT and idle), this thin tube is for idle vacuum which would be totally insufficient under WOT. Cam cover tubes will suffice this purpose.

Here is my train of thought, those suctions tubes that go into left/bottom inlet of "oil separator module" are pretty big plus supercharger also has a hole sucking air from that module. To compensate such a big demand of vacuum, fresh air should have at least similar size pipes. That's why I believe right side/top of module is fresh air inlet to crankcase directly, so it can later mix with oil vapors and blow by gasses and other junk that oil is designed to clean.

Am I on the right path of thinking? If anybody have technical data or manuals, that would be great if I can study them

As I edited in earlier post with a link for a paper, eliminating blow by gas will not reduce IVD.

See page 10 and 11 of this self training guide on brief explanation of Audi PCV system. Connection to intake is slightly different than 3.0L TFSI but operating principle is same.
On page 11, it says that the tube I mentioned is supplying fresh air. You probably saw the connection of the hose to a nipple on PCV when you were doing intake carbon cleaning.
http://doc.mbalib.com/view/cd75d6eb7...a1e863a81.html

Crank case is not subject to full vacuum of intake. That will be a total disaster.
That much vacuum will suck oil and hydro lock the cylinder in worst case.
Diaphragm in the PCV will control amount of intake vacuum applied to the crank case.

[BOPOH]

As I edited in earlier post with a link for a paper, eliminating blow by gas will not reduce IVD.

See page 10 and 11 of this self training guide on brief explanation of Audi PCV system. Connection to intake is slightly different than 3.0L TFSI but operating principle is same.
On page 11, it says that the tube I mentioned is supplying fresh air. You probably saw the connection of the hose to a nipple on PCV when you were doing intake carbon cleaning.
http://doc.mbalib.com/view/cd75d6eb7...a1e863a81.html

Crank case is not subject to full vacuum of intake. That will be a total disaster.
That much vacuum will suck oil and hydro lock the cylinder in worst case.
Diaphragm in the PCV will control amount of intake vacuum applied to the crank case.

ok, thanks for links and info. So PCV is really not that influential, however i still think it does contribute just for the fact that once oil collects on intake valve it does create extra barrier/catching sticky surface for further continuous build up. What options are available then?

What do you think about blocking PCV port to supercharger, any good/bad effects?

Back to original post, VIDEO IS WRONG - DON'T FOLLOW IT

[audi bug]

ok, thanks for links and info. So PCV is really not that influential, however i still think it does contribute just for the fact that once oil collects on intake valve it does create extra barrier/catching sticky surface for further continuous build up. What options are available then?

What do you think about blocking PCV port to supercharger, any good/bad effects?

Back to original post, VIDEO IS WRONG - DON'T FOLLOW IT

Blocking the PCV port will create too much pressure in the crank case and cause blown seals.
As I said earlier it still doesn't solve oil sipping through valve guides.
We are not going to win the IVD battle with GDI.

I know some engines in Europe are using dual injections (direct and port injection) to lower the particulates emission.
http://www.greencarcongress.com/2014...4014-audi.html

New Ford 6 cylinder EcoBoost engine has dual injection too.
http://www.greencarcongress.com/2016...0503-f150.html

Until we trade in our C7 for a new car with dual injections, we have to do manual cleaning once in a while.

I had 2006 MY C6 with 3.2L FSI.
I did manual cleaning at 58k miles, inspected again 110k but didn't clean it (wasn't bad at all), and traded in at 185k.
Only one picture showed the valve deposit in this thread.
https://www.audiworld.com/forums/a6-...clean-2764902/

It had an occasional mild rough idle when cold but had no major issue.
I expected C7 3.0L TFSI would have better handle on IVD then 3.2L TFSI because oil consumption I saw on my C7 was very impressive.

The valves in your engine at 80k miles didn't look bad to me. Although the blobs on the valve stems were not pretty.
http://www.audizine.com/forum/showth...se-should-I-do

[BOPOH]

totally agree with you about valve stem seal leaking oil - no argument there

However, I'm still convinced that PCV is contributing to valve coking, look at these runner flaps, they are far away from intake valve seals plus both sides are dirty. I had to use 3 cans of brake cleaner because there was so much build up that even tooth brush couldn't handle it






Also, tonight i'm going to look at check valve in that tiny hose from intake tube to see which direction it allows air flow. Intakes created vacuum, plus if you check throttle body there is some carbon build up too, which is another reason why I believe that small tube sucking air to assist with positive crankcase ventilation (PCV) pressure. Based on simple assumption that engine needs to create vacuum there must be sufficient fresh air input - it can be that tiny tube, but I think there is something else. Below are some videos in case anybody is wondering about PCV. Even non GDI engine get carbon buildup in throttle body, so PCV system does create issues - which I'm currently researching to mitigate. Once again, I appreciate all input and discussions, so thank you for guiding me! By the way B6 A4 had terrible issue with oil sludge and PCV system re-route is almost mandatory to keep engine running fine, I've had it done and saw a great reduction of carbon build up on my throttle body and much cleaner under valve covers









By the way: audi bug - thanks for your DIY, it was one of couple that I printed out to follow

[audi bug]

However, I'm still convinced that PCV is contributing to valve coking, look at these runner flaps, they are far away from intake valve seals plus both sides are dirty. I had to use 3 cans of brake cleaner because there was so much build up that even tooth brush couldn't handle it

Newer PCV sytem came long way from a simple check valve to the double cyclone and labyrinth oil separator. However, it will not completely eliminate oil mist from the blow by gas. Same for catch can oil separator. I have not seen any oil catch can manufacturers publishing their efficiency numbers other then statement that their catch cans are the most efficient in industry.

Also, tonight i'm going to look at check valve in that tiny hose from intake tube to see which direction it allows air flow. Intakes created vacuum, plus if you check throttle body there is some carbon build up too, which is another reason why I believe that small tube sucking air to assist with positive crankcase ventilation (PCV) pressure. Based on simple assumption that engine needs to create vacuum there must be sufficient fresh air input - it can be that tiny tube, but I think there is something else.

I don't understand your thinking here. There is vacuum in intake because piston suction and super charger boost for our engine against partially open throttle plate. Depending on which position in the intake we are referring, pressure in the intake of a super charge engine gets complicated by boost of the super charger. However, it is safe to say that intake from the throttle plate to inlet of super charger will be in vacuum state. If throttle plat is wide open, vacuum level of intake will drop significantly because now there is very little restriction. Naturally aspirated engine will have no vacuum at wide open throttle because the volumetric efficiency is way less than 100%.
That fresh air from the small tube is to supply air to crank case to displace blow by gas inside the crank case (replenish air volume of the blow by gas being sucked by engine thorough oil separator i.e. PCV system) not the main air supply for combustion. I am stating obvious stuff but feeling I am missing your point grossly.

[BOPOH]

I don't understand your thinking here. There is vacuum in intake because piston suction and super charger boost for our engine against partially open throttle plate. Depending on which position in the intake we are referring, pressure in the intake of a super charge engine gets complicated by boost of the super charger. However, it is safe to say that intake from the throttle plate to inlet of super charger will be in vacuum state. If throttle plat is wide open, vacuum level of intake will drop significantly because now there is very little restriction. Naturally aspirated engine will have no vacuum at wide open throttle because the volumetric efficiency is way less than 100%.
That fresh air from the small tube is to supply air to crank case to displace blow by gas inside the crank case (replenish air volume of the blow by gas being sucked by engine thorough oil separator i.e. PCV system) not the main air supply for combustion. I am stating obvious stuff but feeling I am missing your point grossly.

So my worries are based on information from 034motorsports mentioning of Intake tube collapse under vacuum(I think that's only possible under WOT conditions), which is contradicting your statement: "If throttle plate is wide open, vacuum level of intake will drop significantly because now there is very little restriction." If engine is running higher RPM, there is higher demand for air even if WOT there is enormous amount of air moving into the engine.

Statement from 034motorsports:
This durable, high quality silicone hose was modeled directly off of the factory part to ensure perfect fit and finish, and extensively tested at 034Motorsport with the help of independent Audi enthusiasts. In addition to cloth reinforcement, this hose features stainless steel wire reinforcement to prevent collapse under vacuum. (ref. CLICK HERE)

Above statement makes me believe that there is vacuum, to tell the truth - I was really tired yesterday to investigate check valve direction - that's the only 100% sure way to get answer :)

[ericw.]

I just want to throw something shocking out there that I heard yesterday. My friend had his S3 flagged TD1 at Audi Marin (SF Bay Area) for having a catch can installed.

[audi bug]

So my worries are based on information from 034motorsports mentioning of Intake tube collapse under vacuum(I think that's only possible under WOT conditions), which is contradicting your statement: "If throttle plate is wide open, vacuum level of intake will drop significantly because now there is very little restriction." If engine is running higher RPM, there is higher demand for air even if WOT there is enormous amount of air moving into the engine.

Statement from 034motorsports:
This durable, high quality silicone hose was modeled directly off of the factory part to ensure perfect fit and finish, and extensively tested at 034Motorsport with the help of independent Audi enthusiasts. In addition to cloth reinforcement, this hose features stainless steel wire reinforcement to prevent collapse under vacuum. (ref. CLICK HERE)

Above statement makes me believe that there is vacuum, to tell the truth - I was really tired yesterday to investigate check valve direction - that's the only 100% sure way to get answer :)

That is a marketing statement.
If there is a vacuum build up enough to collapse the clean air inlet tube at WOT, that is due to bad design for both whole air inlet system and air inlet tube itself.
Well, that's what people selling CAI is insisting: factory system has too much restriction and CAI will give more cold air flow hence more hose power.

Ideally you want to have atmospheric pressure form air inlet down to intake valves at WOT, but there will be some pressure drop due to fluid dynamics and restriction of mechanical components: air filter, air tube, filter box shape and etc.
But all that shouldn't be more than 0.5 psi drop (1 inch Hg) relative to the atmospheric pressure (call it vacuum) in the intake system at WOT i.e. very low level of vacuum.

This is a simple way to check intake system design by attaching a pressure gauge (absolute pressure gauge) to the intake manifold.
1. measure intake pressure before engine starting (it will be atmospheric pressure)
2. measure the same during WOT take off
3. the difference will give you pressure drop due to intake system (and give you relative value of pressure/vacuum within the intake system).

See this blog for what intake system pressure looks like relative to the atmospheric pressure (vacuum since he used a differential pressure gauge). The same method can use to verify CAI effectiveness.
http://www.tuneruniversity.com/blog/...iction-part-i/

What I am basically saying again is that vacuum in the intake system should be very low to negligible at WOT to achieve maximum engine performance.
If there is measurable amount of vacuum at WOT, then engine is not going to generate maximum power it is capable. It may be due to badly designed intake system or severely clogged air filter.