Do I have a vac leak?

[StefanoScalia]

Let me preface this that my car runs really well. Except...

I started her up cold (and the weather JUST turned cold) and I noticed that the engine was running a bit rough. Startup idle is around 1k, the drops down to 900 after a few minutes, but it was just noticeably "lumpy" - is this just a cold weather thing? I also noticed I could smell my exhaust a lot more than usual. Running rich?

I also occasionally have an issue coming to a stop, I clutch in and the revs drop to about 850-800 or less then go back up to normal idle. Is this normal?

Any thoughts are appreciated. Otherwise the thing is great - no CEL!

[Xyber]

Take a plug out and see if it has pale crusty deposits on it, that can be caused by a leaking manifold gasket. You could also see what the lambda readings are doing. Do a check on the pipes as well between the MAF and manifold and vac lines as well. It only takes a small crack/tear to send things abit mad.

Vac leaks are a nightmare, I've chased them for weeks in the past

[halik]

Hook up VAG and post MVB 032 values

[halik]

Take a plug out and see if it has pale crusty deposits on it, that can be caused by a leaking manifold gasket. You could also see what the lambda readings are doing. Do a check on the pipes as well between the MAF and manifold and vac lines as well. It only takes a small crack/tear to send things abit mad.

Vac leaks are a nightmare, I've chased them for weeks in the past

Which gasket are you referring to?

[neil08]

when i started my car cold i got the same thing for a while, another az'er/Audi tech looked over the car and i had a secondary vac hose out, if looking at the motor it was on the left hand side right next to the motor. I also had a check valve on the air box melted, may not be the same hose but i would check over for visual melt or tears also A4Darkness engine strengthening thread which where show you where alot of this stuff is located

[StefanoScalia]

Hey neil, thanks! Do you have a link to that thread? I want to examine those things but I did a search and couldn't find it. I'd appreciate it.

To everyone else, thanks alot. Gonna check it out this weekend.

[jfunkey]

Hey neil, thanks! Do you have a link to that thread? I want to examine those things but I did a search and couldn't find it. I'd appreciate it.

To everyone else, thanks alot. Gonna check it out this weekend.

This is actually normal on cold starts. The GIAC chips obviously don't adjust for cold starts with added hardware.. This is semi close to what the stock car will do. In colder weither the car is going to run rich on start up to help warm the car up quicker. If you start the car 4 or more times and this happens with no CEL then its safe to assume your not having any serious issues. The question is will it do the same thing when the car is warm??

I would check the motor to see how this reacts when cold. If this happens again. Start the car cold and pop the hood.. take a good look and listen close to the motor. If there is a leak you should be able to hear something..