Unofficialbmw.com

[donny]

My engine idle erratically when it's cold or in the morning when the start at hte first time. But the idle will normal after the engine warm enough.
What should I have checked?
Thanks

[2002kid]

Check your idle control valve. It's the "D" battery sized unit on the right hand side of your upper intake area. Try tapping it with a screwdriver handle, and see if the conditions improve. If they do, try unclamping the valve asy., and check for carbon build up inside the valve body. You can clean it out with brake cleaner or another type of solvent, reinstall it and it should be o.k. Also, you may want to unplug your 02 sensor, the plug is located at the firewall on the passenger side coming out of a black tube from the back of the cyl head; unplugging it won't hurt running conditions, and ususally improves them. Also, your idle control unit may be going bad. It is located in the glove box under the upper plastic panel next to the ECU. They can be bought used fairly inexpensively but new may be a few bucks. Check out: www.eurodepot.net for new and used parts discount pricing, good luck!!! :)

[dale]

Check out this page on the subject:
http://www.unofficialbmw.com/repair_faqs/idle.html

And this FAQ:
http://www.unofficialbmw.com/faq/FAQ.7

Dale