E36M3

iTrader: (1)

Why does my idle tend to go up between 1100 - 1200 rpm after the car sits for couple of hours. It will go back down to 600 rpm after five minutes or so. I don't believe I have vacuum leak.

I searched and read several threads pertaining this but none mentioned about the issue that I'm having. I also understand these cars will take 10 minutes for the rpm to go down upon warm up (mine does) if sitting overnight but not couple of hours. Is it normal or I have an issue elsewhere?

SpencerT

What does the temp guage read after a few hours?

When I start mine (ambient temp 45 F) it idles around 1300 but quickly drops
If the guage is 1/4 up its is about 900-1000
guage 1/2 of the way up (operating temp) it is 400-650

E36M3

iTrader: (1)

The temp gauge sits all the way down after few hours of driving, and the ambient temperature is around 60 or higher.

My temp gauge is identical to yours the only difference is the ambient temperatures. So is it normal?

Yamae

I don't know this is related to your symptom or not but I'd better to inform you that my 98 Celsior had a similar high idle problem after warmed up.

The cracked ventilation hose between the PCV valve and the throttle body below was the root cause. The crack was at the bottom side of the hose and I could not notice it by my eyes. The whistle noise was sometimes heard and I finally could find it out by my ears.

E36M3

iTrader: (1)

I will check that hose. Hey thanks a lot.

SpencerT

If your idle drops as the engine warms, I wouldnt worry.

door331

The engine will idle higher when the engine is cold and then lower after it has warmed up. I also notice on mine that if I am in P or N that the idle raises to about 800-900 but if I go in D or R then it goes back down to the normal 600.

E36M3

iTrader: (1)

Mine does the same.

E36M3

iTrader: (1)

I appreciate all the inputs. I guess I have nothing to worry about. Thanks a lot guys,