Posted by Peter Florance on September 01, 2004 at 04:47:37 from from 65.120.51.31
In Reply to: My 81 528i has a very rough idle posted by Jared Lazaron on August 31, 2004 at 13:40:17:
Congrats on the purchase. Hope your mom is doing better soon,
Vacuum leaks are a good place to start. Examine all the vacuum hoses and intake boots (especially between throttle and air flowmeter (underneath).
If O2 sensor is unknown condsider a new one. Generic Bosch can be used; crimp onto wire of old sensor retaining the old sensor's connector to car harness. This car never had a lot of emissions stuff which is why they can run quite well for a long time
If car has not received regular maintainance I would get the valves adjusted by someone who knows BMW M30 engines. Tight valves can cause these engines to run rough; probably vacuum leak though. At adjustment time they should check torque on oiler tube bolts (if they don't understand this; find someone else who is familiar with this problem). The bolts back out and starve the cam for oil. There is an updated part. Big 6 engines need2 of them.
Also if brake fluid is nasty and black, get it flushed as well.