I have a '90 525i and love it! The car has a very rough idle. I have read a bit on the O2 sensor, and was wondering if it could be causing the problem with the idle. Pretty sure it just idles on 5. No signs of a blown head gasket, cracked block or anything like that.
Any suggestions appreciated.
Also - Is it hard to change the thermostat on a E34 M20 2.5 Where can I get some instructions from?
BTW: #2 plug is always dirty with soot whenever I check them also. Related?