cause of leaking cam cover gaskets??

[wozza]

Well air will only flow one way on the new one as it does on the old - so all you need is an air source.. I just used a clean piece of tube and blew through the valves, once they were off to check the seal and to figure it out...

[andream88]

Sorry - picture says a thousand words so see attached!

In the pic on audi world yeah it's the green valve my car has a black one with an extension coming off it for the brake servo. All were leaking slightly but the one going to the crankcase breather had the main issue and will be why, I believe the oil seals are blowing out.

Along with the small hose pieces, all the valves total cost was about 60 quid. But carb cleaner is a cheaper alternative possibly.

ps: I also replaced there are other green non return valves on my car that were duff, but these were not related to this problem.

Hi guys should i replace the Pressure limiting valve and the crankcase breather when ordering all the other valves?
They're not sold separately. I need to buy the whole Spider Hose thing, and it's not cheap.

Please answer!!

Thank you very much

Andrea

[wozza]

The spider and pressure limiting valve just tends to get gummed up - so I just used carb cleaner (not brake cleaner) and cleaned it out. The same can be said for all/most of the valves in the oil breather circuit if you don't want to splash cash.


Ultimately the valve that stops boost pressurising the crankcase is a little black one at the back of the inlet manifold (on the diagram I did it says 'duff valve') to which the spider distribution piece connects. The vacuum pump (which doesnt contribute to this problem really) is just a venturi and limits the amount of air drawn in - I zapped it with carb cleaner too as I had it all in bits - seems fine still. The green valves in the vacuum circuit (also labelled 'duff') need to be replaced if once off the car, if they don't block in one direction the flow direction is marked with an arrow - think they get affected by heat mostly and the plastic diaphragm gets warped internally.

The above will help stop oil in the Y-pipe and stop it getting drawn into the intercoolers (as an illustration I had about 100cc in each of mine - at the cars first cam belt change). The crap in the little black valve can get caked on and may stop a decent seal so watch it - it's a one way valve so you can test once cleaned.

[wozza]

sorry got carried away - the green valves in the vacuum circuit will help with air leaks and lumpy idle/dodgey mixture, not oil issues.

[Philws4]

Is this booster/suction pump fitted to the S4 as well or is the one way valve to be replaced at the bottom of the F hose? In which case might as well do the F hose delete while i am at it

[neckarsulm]

Ordered the suction pump today and it was only £17 + VAT from Audi.
Also 1 of my green valves was duff the other was OK (replaced the two).
Cracked it open and the diaphragm had come off it's central prong which used to hold it in place - it was blowing through in both directions (which is bad!).

Ordered all the other bits too.

[neckarsulm]

received mine today looks like the same as yours with the extra points. Also cant seem to find an arrow on the new one to say which way to fit

any ideas?

I finally got my back ordered one way valve and like those bought by others it looks nothing like the one already one the car as it has 2 or 3 more small pipes off it.
Is this correct and are people just looping it back with a small piece of hose to block these outlets off?