90 535i, Vibration at idle and under load???

[Guelphguy]

This is the one problem I have to fix, driving me nuts, just got the car Saturday, private sale...long story, car was immaculate, good price just a vibration issue I knew I was going to have to deal with.
So, the symptom is that there is a vibration felt through the car while at idle in drive and when accelerating under load, cruising feels ok.
At first I thought it may be driveshaft related..needing to be balanced but that does not make sense as then it would be felt all the time and since there is vibration stopped at idle...don't think so. Then thought either U-joint or motor/tranny mounts? So I bought the car thinking I was going to have to fix something like that.
Now, sometimes when the car is first started the "service engine soon" light comes on and the car seems to stutter and then quickly the light goes off.
So now my thought is, what about electrical like ignition coils or wires, if one cylinder is not firing, would that not be felt at idle and under load??
Any ideas??

[632 Regal]

you got it I think! probably a slight miss which could be from anything like a weak coil, wire, injector etc. I had the same sort of deal when I got mine and did ALL the expensive fixes and then finally replaced the short coil to plug wires and the problem went away. Start with the crap fixes forst and work outwards not like what I did. However I know I dont need coil packs, injectors etc now.

[George Davis]

I wouldn't rule out electrical problems, but my '94 525i had a funny vibration that we usually felt under load, but not all the time. New motor mounts cured it.