[billymade]

A common problem; is the PCV valves fail and this causes, a air leak (requiring a new pcv or a whole new valve cover). Have you scanned the car for trouble codes?

Here is a thread; about the PCV failure issues, that are common with the 2.5L engine:

http://newbeetle.org/forums/2-5-liter-gas/65633-re-2-5l-pcv-valve-failure-solutions-dorman.html

 

[billymade]

I do not have a 2.5L Volkswagen; I did replace the PCV with a Dorman repair kit, in a Jetta, the owner complained of high idle, the car dying intermittently, check engine light on and overall, just odd drivability problems.