[edgemar]

Pelican Braintrust:

This has been driving me crazy and I've not found a solution after weeks of searching all the BMW forums. Please help!!! it's a 93 325i bmw.

I've spent a bunch of money to catch up with all the deferred maintenance on this car and it drive greats except the engine shakes at idle. It has a rock steady idle but you can see the engine shaking in the engine bay and the car vibrates. It hasn't always done this...only in the past month or two. It idles at about 550 rpm...

I'm thinking now that the car has a low idle for some reason...any additional rpms and the engine seems to smooth out. The engine performs fine while driving along.


Here is what I've done so far to try and fix the issue:

1. checked each coil for operation
2. checked resistance at each coil per bentley with multimeter
3. checked visually for vacuum leaks.
4. replaced fuel filter in june.
5. replaced spark plugs with NGK BKR6EK
6. Running premium chevron gas and put techron last fillup.
7. unplugged map sensor to see if there was any change. = no change
8. replaced motor mounts
9. replaced fan clutch
10. bled coolant system
11. clean air filter installed
12. no arcing of ignition components observed
13. no or very little oil in the spark plug holes.
14. replaced all coils.
15. cleaned idle control valve.
16. no codes it's OBDI

- replaced the vanos a few months back with dr. vanos rebuilt unit.

Any thoughts would be greatly appreciated!!! This thing is driving me crazy. I bought some new Bosch plugs but i don't think it will make a difference.

I'm also willing to take it to an expert. If anyone knows someone that's really good with old BMW's please chime in!

Thanks so much for your help!!!