HELP uneven idle speed

[tol4o]

When I start the engine, it works uneven on idle. The engine speed changes between 600 and 900rpm. I can hear the exhaust sound in the rear skipping. The same situation when the engine is hot. When I am on first gear and leave the car to run on idle engine speed the car is shaking because of uneven engine rpm.
The car is running good and there is no problem when driving. I can notice this problem only on idle speed.
Do you have any idea what can cause this problem. I installaed Bosch Platinum 4+ about 10k miles ago. Recently changed the belts, valve cover gasket and oil filter can base gasket.

[PettitWC]

there was a thread about this not too long ago. I think the consensus was to check for leaks in the vacuum boot and if there aren't any then clean/replace the idle control valve

[tol4o]

Ok, I found what is the reason for my problem. After I inspected the hoses I found out that there is a vacuum leak from the valve cover hose #13, right where the connection is.
http://www.realoem.com/bmw/showparts.do?model=CG73&mospid=47506&btnr=11_1562&hg=11&fg=15

I guess that when they changed my valve cover gasket, they had a hard time removing the hose from the cover and they damaged it. Additional to this they did't put a hose clamp back to keep it tight and secure.
I will use hose tape and a new hose clamp to fix the problem, because if have to change it, I have to involve the second hose which is a part of the cooling system and it's gonna get messy.

[PettitWC]

that'll do it