zao177

Hi all
I've having squeaking noise trouble with my 2007 Q7 4.2 FSI.

[Noise on YouTube]

[Noise Occasion]
-Start up and cold temp: NO ISSUE
-Temperature goes up to the middle of temp gauge: Start squeaking
-The noise goes away when revving up.
-Noisy at idling to 2,000rpm (2,000rpm or above go away)

[Parts I've changed]
-Tensioner Pulley
-Idler Pulley
-Accessory Belt

[Status]
Still having noise issue…

Your advise will be greatly appreciated!!
Thank you

zao177

Resolved!

[Issues]
-PCV Valve Failure
- P0174 P0171 Bank System Too Lean

[Replaced Part]
Part#: 079103464D

PCV Valve Diagnosis:

iconoclast

well done. nice write-up... thanks.

MDK993

Wow you were not kidding, that was a serious squeal. Nice write up. Thanks

bozack

nicely done. I had posted that up awhile back and had the exact same issue as you could hear that squeal from blocks away. The dealer keep thinking it was a pulley or something and had no idea.

Finally had a Mercedes buddy narrow it down and I took it back to the dealer where it was the fuel regulator if that is the same part #

iNfiNkC

wow, glad you found it, i would have never guessed that sound was coming from the pcv.

zao177

Thanks for the comments guys!

My total expense for this work was:

<Expense from Correct Diagnosis>
-PCV Valve $218

<Expense from Incorrect Diagnosis>
-Tensioner Pulley: $140
-Serpentine Belt/Accessory Belt $30
-Idler Pulley $35

Total $423

igotag

So I've had a suction on my oil cap, just replaced my PCV, still have a suction. When I pull the oil cap the engine starts to run rough. Any ideas?

rooster26m

Well, it's gotta be in the EVAP system...mine developed the train whistle at idle as well. Gonna replace the PCV in a few days...

testarossaguy

IGOTAG....I believe that the "suction" is normal for the crankcase ventilation system.