rough idle caused by air leak

[dixie600mhz]

My wife's 2006 2.5L new beetle convertible started to idle erratic yesterday. The car would almost stall then idle up to 1500rpm then almost stall. It only happened when sitting still at idle. Drive-ability at speed and acceleration felt flat but it was still driving. On the first day there was no engine error code but this morning I managed to pull two.

The codes were
P2279- Intake air leak detected
P0507- Idle speed faster than normal

After some troubleshooting tonight I managed to nail the problem to a ripped diaphram inside a psuedo PCV valve on the front of the valve cover. The part is called the pressure regulator valve for crankshaft housing ventilation. The down side is that I can't seem to buy it separate from buying a complete valve cover. A new valve cover is $136 plus shipping. Check out the rubber piece that's causing all the headaches.

engine bay
http://img199.imageshack.us/img199/2055/enginebayp.jpg

cover diagram
http://img228.imageshack.us/img228/4...verdiagram.jpg

parts
http://img203.imageshack.us/img203/5138/componentss.jpg

rip
http://img704.imageshack.us/img704/7213/ripb.jpg

FYI, I could hear this thing leak and could feel air sucking in the little hole in the bottom of the outer cover of the valve. I had the classic air leak symptoms where I couldn't pull the oil cap off with the engine running. When I shut the motor off I could still hear it suck air in for about 5 seconds through the faulty diaphram.

Hope this helps others that might suffer from this problem. The car is just over 3 years old with 62k miles. I can't believe this rubber part might end up costing $150???

[hamsman]

Can't give you any info on the parts, but just wanted to say that the way you posted it with great photos will surely help someone else down the road.

Good luck on finding just the part, if you do, please post.

Don, aka.....the hamsman

[dixie600mhz]

Hi Don, so it really did end up in buying a whole new valve cover. The upside is that it only took 20 minutes to fit last night. The car is now idling like new. All fixed.

Sucks it cost $150 to repair a ripped rubber part. My vette is cheaper run! No more VW cars in my future based on this adventure! FWIW, our toyota has covered 100k miles in 5 years and has only needed oil changes and tires. Lexus and toyota from now on.