1999 528I rough cold idle and stall

[Highgear]

Anyone have an idea of what might be the problem? The car ran fine in the Summer, but now that the morning temps have dropped the car will run fine for a few minutes but then get rough and stall.:help

[jase007]

1. vacuum leaks
2. vanos seals - www.beisansystems.com

[Highgear]

If it was the vanos seals, wouldn't it through a cel code?

[gdp]

not necessarily. Mine had similar symptoms a few years ago without an engine light. I changed the vanos seals and all is better. There was an effective test I performed to try to pinpoint the vanos unit. If you unplug the solenoid when the car is cold and the problem goes away, it is safe to say your vanos needs work. That procedure worked for me.

[supark]

in my 528i with the vanos seal issue it didn't trip a CEL. You can tell usually by the fact that the idle fluctuation is super regular - you can pretty much time the spaces between the idle dips

[jase007]

If it was the vanos seals, wouldn't it through a cel code?

Like mentioned, not necessarily. Mine didn't.

The Vanos symptoms are classic and easily identified (while warming up from cold in <50F the idle oscillates and ICV -idle control valve - catches the engine and prevents from stalling ... for a while).

Easy to diagnose ... disconnect the electrical connection to the solenoid (forget if it was intake or exhaust) the night before. Go to sleep. Next morning, start car from dead cold with vanos solenoid still disconnected ... observe if car warms up through "blue" zone and reaches normal operating temperature without any idle oscillations / jolts.

Here is my experience and writeup (http://www.bimmerfest.com/forums/showthread.php?t=262793&highlight=) (partial - to supplement Beisan).

:)

[Johntee540]

This is a fun repair to do - and if you arent silly like me - you wont need to buy 2 Besian Seal kits! thanks Jase for having an extra set laying around after I screwed up the set I bought. - JT