Expert: Don Berlan - 10/12/2007

Question
As I stated the car is a 1985 528e.

It is acting very strange:

a) the gauges on the panel (gas gauge, temp. gauge, rpms) stopped working; the speedometer still works when the car is driven.

b) the car revs when it is in park or neutral

c) the car accelerates when I idle it...I have reached speeds as high as 40 km/h (~25 mph) when idleing.

...I know the problems don't seem like they are related, but I'm sure they are, as I have experienced the same symptoms a couple of times the last few years (usually it corrects itself...this time it hasn't)

Any ideas or suggestions you have are very greatly appreciated.


Answer
The gauges sounds as if there is a bad ground,check them they are under the drivers kick panel.As for the reving you need to take care of any oil leaks that you can see,clean the throttle opening,making sure it is about .002 inches.Clean the idle control valve.The system is a close system.By that I mean there is no PCV valve,so any oil leak will cause an uneasured air coming into the intake system and the AFM cannot adjust itself properly.Besides the unmeasured air it causes oil to be drawn in and makes intake system dirty.