Kardell

Hi All,
I have a problem with car idling.
After some driving when stationary it happens that RPMs stay high around 1100, but it keeps changing, something it is 850, but you can hear it struggles like it is choking or something. Sometimes it is fine, sometimes pretty rough, but it never dies.

So in terms of parts this is what was replaced recently, but this particular problem was before and has not improved.
1. MAF sensor
2. N75 valve has been replaced (this has addressed issue with jerking acceleration)
3. new spark plugs
4. new ignition coils

What in your opinion is next in the line to be checked or basically replaced.
Cheers

B6 Turbo

Check Vacuum/boost lines, boost leak test would help. Also see if your throttle position is changing....

John535is

Agree - PCV or vacuum lines.
I ended up pulling the inlet hose and using a cap and compressed air found the crankcase breather (that's the pipe under the inlet manifold) had a vacuum leak. Theres also a little check valve in the T on that hose.

B6 Turbo

I had a broken check valve... I probably broke it when trying to fix the coolant flange, bought a replacement but decided to play with the broken one and JB weld it back together and tested it... surprisingly it works lol