First and forthmost i did a search and wasnt able to find anything.

I have a DD 98 M6 TA with 125k miles and replaced my power steerting pump, alternator and belt. Now the damn things seems to surge for an unknown reason.

When i let the car coast in netrual the rpms read 2k. As i come to a stop and about 3 seconds later the car idles around 1600. At times, it drops down even lower around 1100 rpms. I also found that when i turn on the a/c or heater the rpms increase to around 2100 at a dead stop.

Im confused as to why it may be doing that. Could it be the belt? BTW, its been a week and a half and nothing seems to be going back to normal.

I hope im in the right section and you guys can help me out here.


thanks

EDIT: Car is stock with the exception of LT's.

 

It's natural for the car to idle up when the AC is turned on...that's not an issue.

I don't see how the belt could be an issue if you replaced it with the exact same thing...

Perhaps you accidently pulled a vacuum line loose during the install? I'd go back and check those over to be sure...

 

Def. sounds like a vaccum leak somewhere. Check to make sure all the hoses are reattached if you don't find one that is off look at them carefully and make sure none of them are cut, nicked or rotten.

Then check all your sensor connections.