# A4 2.8 30v - trouble with idle



## Disturbd1 (Jan 26, 2007)

Just replaced my radiator a week ago (original was leaking), and for some reason now I have idle problems. I doubt the 2 are related, but one can never be too sure.

What happens is that when I run/drive the car in the morning while it's cold, I usually don't have any issues until the engine warms up to operating temp. I notice that once there, if I am coming up to a stop and put it in neutral and just brake...the RPM gauge drops way below the normal 500-700rpms that it idles at, almost to the point of choking/dying. Then it goes back up to ~1000, and bounces a few times before it evens out. This consistently happens every time I take it out of gear. I have noticed that once it evens out, it seems to idle OK, a few random bounces aside (all bounces are referring to visibility on the RPM gauge, of course).

Any ideas? It was suggested to me that maybe my TB needs cleaning. Has anyone experienced these exact symptoms?


----------



## Disturbd1 (Jan 26, 2007)

Scanned for codes yesterday - nothing. If anyone has any ideas other than TB or ECM, let me know! :thumbup:


----------



## O_o (Nov 12, 2009)

I'd start by checking for a vacuum leak, and the EGR/combi valve.


----------



## Disturbd1 (Jan 26, 2007)

Almost all the vacuum lines were replaced about a month ago while it was in for repair. Is there a way to check the EGR valve without just cleaning it to see if it makes a difference?


----------



## O_o (Nov 12, 2009)

If you can blow through it when the engine is off, then it's stuck open.


----------



## AndyTR32 (Jun 4, 2003)

It's probably worth cleaning the throttle body. Mine started doing the exact same thing this week. I thinking it's the TB since it started during the first cold day of the year


----------

