sushistrip

'13 A8 4.0T. I had a CEL for Intake Leak (P2279), there was also an audible "air-escape" sound coming from near the PCV in the V, very noticeable when I turned the car off. I replaced the PCV valve and all relevant gaskets/seals. The air-escaping sound is gone, the CEL is gone, however the suction through the oil cap and oil dipstick tube are still present, also the rpms will increase. Car drives perfectly fine, makes good boost, idle is smooth as silk. Is this an issue I should continue pursuing or just leave it be?

It also might be worth mentioning, my idle vacuum is 15.7psi at around 550-580rpm, does this seem low?

Any advice is much appreciated.


Side note: If anyone would like to tackle this project on their own, I can do a write of my experience. I know there is a write up on audizine for an S7 but they do about 250% more than what's needed on the A8. I used alldatadiy service manual, which was comprehensive enough.

Roldie78

I have a 2013 A8 4.0T and dealing with the exact same issue. I replaced the PCV but am still experiencing strong suction. How did you resolve the problem?

ssblacksb

I would like to know more on how to replace the PCV please and thank you.

2010A8Lsport

I know my 2010 A8 is a generation behind but mine is also experience the high crankcase vacuum...

Curtis Mueller

Did anyone fix this vecuum problem? I have it on my 2013 S6, PCV just replaced.

A8L_New_England

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This is the D4 forum.
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W84me

Is there any update about this, I am facing the same issue. Vacuum present even after the PCV is replaced. A8 2016 4.0T

A8L_New_England

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Please allow me to bury this. There are several other threads covering PCV / vacuum issues in the 4.0
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The most productive approach for you and the forum is to do some searching and reading, then respond to those threads.
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Cheers.
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