1992 BMW 316i idle issues

[mholland12]

Here receantly I had to do a bit of work to my car. I had to replace the water pump thermo stat and raidiator. About a week after I did all the work the idle started to act up. When the car is cold the motor will run very ruff. Like it is missing on a cylinder. But after a minuet of running it will smooth right out like its supposed too. I have no problems with power after it warms up. I think after I over heated it I might of messed up the spark plugs. Does anyone have any ideas.

[Lord Vader]

How badly did you overheat it?

Take a look at your vacuum lines and intake boot. A crack or tear in the line can cause a rough idle. Best place to start as its most common, and usually cheapest.

[mholland12]

It over heated pretty bad. It over heated three time on the Autobahn. Each time that it over heated I pulled over and let it cool. Come to find out I had air in the coolant line thats why it kept over heating. The coolant line by the cap came off all three times. Now everything has been replaced. Could the O2 sensor be the issue?

[mholland12]

All of my vaccume lines are ok, none of them have any rips or are falling off