[va_samiam]

I am 50% sure I know this problem. I just had the intake off and when I put it back I cleaned it well. The gaskets looked worn and there was some crusting (Caked harden oil) on a couple of ports. I cleaned it all of and reused the gaskets.
So I think it is an intake leak.
What do you all think?

 

[va_samiam]

RV sealant on intake manifold?

I almost put RV sealant when I assembled it. I did not because I was thinking I will be taking it off again for the next problem.

 

[va_samiam]

Weird it musted need to heat and cool to seat itself

It cleared up. I need to read the error codes on the ECU. But it has been running fine.

 

[billymade]

On the 2.5L: they have had issues with the pcv valve diaphragm failing in the valve cover but it sounds like you fixed the issue?

Anyway, Dorman sells a repair kit; something to investigate if your problem comes back. I installed this on a 05 Jetta 2.5L; that way having idling problems, easy install and fixed the problem!

Dorman 917-064 PCV Diaphragm Repair Kit for Volkswagen
by Dorman

https://www.google.com/search?q=dor...j7&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8

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