Problems with PCV system

[AndyP]

Before my car was mapped, only had 0.4bar boost, I had a problem where I was getting a fine mist of oil blown past the oil filler cap. I changed the pressure regulating valve and the one way valve in the PCV system and it seemed to cure it, no more oil mist. Since the boost has now been turned up to 1.4bar the problem is back, but worse. The cam cover is pressurising and blowing oil past the filler cap, and I'm getting quite a bit of oil blown into the MAF hose. I have 2 questions:-

1. What part of the PCV system is failing to allow this to happen? I've checked the one way valve and it seems ok, not sure how to test the pressure regulating valve.

2. Can the std system cope with a bigger engine ( 2.5 stroker ) and a bigger turbo, GT3071 with 1.4bar boost?

[cooperquattro]

hi andy
do you have the pcv piped up as per aby?or 7a cam cover?

displacement has nothing to do with the pcv system,so all should be good on that side...
is the rocker cover clear..ie not blocked in the breather




also....
what were rolling road results? any plots?

[AndyP]

System is std 3B, but with a 7A cam cover drilled to fit the breather at the rear.

No rolling road results yet, it supposed to be on the RR at MRC next month.

[A80Avant]

andy, i think that was the problem with my engine and now it needs a rebuild. Im at the last leg of my journey coming back in the UK and i definitelly will need a rebuild as i think there is something definitely wrong with the engine, basically with the low compression and the 'not pulling' anymore feeling i have had all throughout the journey. Ridiculus really as nothing happens until 3500-4000rpm and the car feels as it has something like 7.5:1 compression

Although i have no oil consumption and have done quite a few kms now, mostly on cruise though, i must say that the one thing that i had never done on the car was a proper PCV system. This after almost 100K kms may have caused the current wear. I would definitely go for a proper dual tank setup as i have now to allow the engine to breathe normaly.

I think on the system, higher boost pressure is causing excess blowby which has to run through small diameter hoses and drain out to the turbo inlet. I had the excact same problem on my engine when mapped, with the MAF getting hammered with blowby in there.

Get yourself some proper tank(s) made and it should be fine, before you allow the pressure to ruin piston rings or cyl head parts...

[UrS4boy]

Andy: Here are some links to some PCV system info:

AAN-related info post (similar to but different than ABY system)

http://forums.quattroworld.com/s4s6/msgs/22506.phtml

A previous S2 forum Thread worth reading:

http://www.s2forum.com/forum/showthread.php?t=50806&highlight=PCV

ABY (and probably 3B) PCV plumbing:

[AndyP]

Thanks I think I've read all your posts on the PCV system today

And after doing so, I can't believe I've overlooked such an important part and expected the std system to cope

[Thuppu]

Nice info on quattroworld and of UrS4boy, but you seariously need to do something to the quattroworld forum so that a normal human being can find something from there. How do you read or find anything when the look is like this? http://forums.quattroworld.com/s4s6/

[UrS4boy]

Nice info on quattroworld and of UrS4boy, but you seariously need to do something to the quattroworld forum so that a normal human being can find something from there. How do you read or find anything when the look is like this? http://forums.quattroworld.com/s4s6/

Funny that. quattroworld exists because AudiWorld switched from Kawf to vBulletin against the forum users wishes. When the switch was made March 16, 2009, we hated it (vBulletin - format they implemented was nothing like this one (the S2 forum)). We had been getting on quite well in Kawf with using the subject line as the one line answer or the start of a longer comment, post, etc. In the background, a new forum, in Kawf, was being developed and on March 17, 2009, it was launched and there was a mass exodus from AudiWorld to quattroworld. The Kawf format was the same that we had grown to like (and still do). It has a good Search function and we have a FAQ sticky (in which I have parked my Engine Bay and UrS Chassis maps):

http://forums.quattroworld.com/s4s6/msgs/15184.phtml

I had started the original FAQ at AudiWorld and stayed on as a member to "protect" and care for the FAQ. The format for the FAQ was not as good as with Kawf so the Audiworld FAQ has diminshed.

Of the various vBulletin Audi forums, e.g. Audizine, Motorgeek, and this S2 forum, I like this (the S2 forum) set up the absolute best. I had even pointed the AudiWorld peeps to S2 forum to use as a model but they ignored my suggestion.

So personally, I am happy with the Kawf format, particularly with respect to the ability to keep and maintain a FAQ, and we (the users) like the conversational style and the ability to scan a complete thread at a glance.

I am completely ambi-forum, i.e. I know the html formats for posting photos and hyperlinks in both Kawf and vBulletin formats and am happy to *try* to help out there and here.

Kawf is not as bad as it looks (to you).

[Jamo]

I could have told you stock PCV and strokers don't mix lol