Bob 2KS4

My wife has a 325ci (I tried bimmerforums.com and they seem clueless) and the idle speed when cold seems to oscillate between 500 and 1000RPM when the engine is cold. Once it warms up it seems fine. When cold the frequency of the oscillation is about 1 or 2Hz. If I pull up to a stop sign cold it will oscillate for about 30 seconds and gradually settle at ~700RPM, almost in a dampened sine wave sort of fashion.

Any thoughts. Your welcome to bitch at me too... I know I'm way off topic

Bob

Bob 2KS4

OK, searched via google.. what I've discovered is something that BMW calls VANOS (the variable valve timing system). Apparently this could be the source of my problem? I donno.

Indyxtype

Could be a multitude of things. First I would recommend scanning the ECU for any fault codes, if there are any, that will help you track it down and in some occasions, even just clearing them out could solve your problem. Your spark plugs might be fouled, or even the incorrect spark plugs depending on who has been doing service on your car. Might be an issue with your ignition wires or various other things related to the electrical system, or it could be something totally unrelated. Unfortunately it would be hard to say one thing or the other without looking around and doing diagnostics or trying a few things. Most decent shops with good mechanics should be able to help you.

Ferris TMK

It could be a couple of things. What year, is it new to you or have you had it awhile?

I have a feeling it'll be the coolant temp sensor or related to running in open looped mode.

The vanos problem from what I recall lead to a CEL and stumbling. The vano is expensive but there are aftermarket rebuild kits. The problem is bad seals but bmw say to replace the whole unit.