idle problem

[gman]

I've already changed the 02 sensor and thermostat!!

I have a 98 328i and I can't seem to get rid of this idle problem. When I first start the car, the idle jumps up and down maybe 3 or 4 times before stabilizing. It also shakes a little ( slight jumping in rpms ) when im stopped at a light or something. Does anyone have any idea what the problem could be or any other solutions??

thanks for any advise, love the site!!

[TECH]

It's not the oxygen sensor or the thermostat, for starters........ :P

Check the intake manifold gaskets and intake boots and hoses for vacuum leaks. Spray brake cleaner around these areas while the engine is running. If the engine picks up speed, or perhaps stumbles from the brake clean, then you have a vacuum leak.
If that is ok, replace the idle valve, or try cleaning it out. Remove it, clean it out good with carb cleaner, and reinstall it.