Rough Idle

I have a 99 with the 4 cylinder engine. It has 97000 miles. It recently sat for a long time and then I replaced the tranny. Now it surges and idles pretty rough. It almost dies when I go through a car wash. Any suggestions on where to look first. Thanks

Hi mate i have a rough idle on my e39 523i and i have posted on various sites to see if some one could shed some light but it could be a number of things so i suggest the best way to find out what is happening is to take it to the main dealer or a garage that has diagnostics and ask them to run a test, thats what i have done and when they run the test they found four faults from the air flow mass meter right back to the lamba probe but i was told that one fault could cause all, so they have cancelled the codes and told me to run the car and go back next week so they can run another diagnostics and see what fault code comes up then they will know exactly what it is and get it repaired mine has 96,000 miles.

I have a scan tool and there are no fault codes yet. I am going to start testing it one of these days. I am just courious what some other problems might be. thanks

Mines a 95 626 and had the same ruff idle probs. I cleaned out the MAF (Mass Air Flow) with sum carb cleaner - reset the ECU and that part runs fine.. The job takes about 10mins even for a n00b like me :lol: