Had this problem. Turned out to be the speed sensor was flaky. It's here: http://www.realoem.com/bmw/showparts...48&hg=33&fg=10
The cruise control seems to work good for a period of time... say... 10 minutes maybe? Afterwards, it accelerates, releases, accelerates to maintain speed. Isn't it supposed to hold throttle smoothly instead of picking up speed and dropping over and over again?
Now about the timeframe... perhaps it's not duration based. Either way, it's quite annoying.
Had this problem. Turned out to be the speed sensor was flaky. It's here: http://www.realoem.com/bmw/showparts...48&hg=33&fg=10
I had this same problem. the curise would only hold speed for about 10minutes, then slowly slowly slowly decelerate.
The problem when away on its own, but the speed sensor might be a good start. A used cruise control module is cheap and i bet its not too hard to reach in an m30.
could it be the speed sensor if the speedo on the dash is reading correctly? i have the same problem but it is heat related. cold day on the highway it works well. a few stop starts through town and the temp gauge rises up a bit and it is all f''d up again.
1994 540i Auto
live fast; die sideways
13.3 @ 104mph (not in the 540)
15.4 @ 150 Kph in the 540 (24/9/07)
You mean the cc has the hickups, esp when hot? Most likely as suggested the speed sensor.Not hard to tell when the speedometer flickers too.
Cruise control... it just goes up and down. Not a lot mind you, but JUST enough to be noticable it's going on and off the gas. Like a slow pulse. Don't really see it in the speedo.