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Discussion Starter #1
2000 328i w/ Manual Trans.
67k on the odo, it has been exhibiting this problem since about 40k, in cold weather. Dealer has had it twice and cannot pinpoint the problem, no codes in the DME.

Cold morning, cold start, with car sitting in the driveway running while I load up my stuff for the day. Car runs fine for 2-3 minutes at cold idle. As the temp needle starts to leave the blue zone, the idle will suddenly drop (500rpm) and the car almost stalls....then it catches itself and roars back up (1200rpm)....it sits there and will cycle like this every 10 seconds or so, as if trying to cross from cold idle to warm idle but it cannot successfully complete the switch.

Eventually the car is able to switch to warm idle, rpms are smooth and the car warms up the rest of the way.My guess is that the sensor telling the car to switch to warm idle is gone bad and is doing so pre-maturely, before the car is able to run at warm temp settings.

If I start the car and immediately drive it, it runs great.

The dealer reflashed the DME last winter, which fixed the problem for a few weeks.....then it came back. They just installed an idle control sensor (not sure exactly which part) and it made no improvement.

Can anyone advise?

Thanks, Ben
 
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