losing power/stuttering over potholes

[jdusty4]

Apologies in advance for a slightly vague question. I searched around a bit and didn't find anything that seemed to apply to this. This morning while driving to work my 87 325is suddenly slowed down a couple of times. The rpms jumped down, and I think I saw the coolant temp dip suddenly as well. The same thing happened on the way back, and I noticed it was happening only while accelerating going over potholes or bumps. I thought this might be a battery problem - I have yet to check whether the battery is good but the connections are tight, the battery is not that old, and the car did not otherwise lose power (all lights stayed on, etc). I recently had the engine relay replaced, so I would assume I can rule that out. Could it possibly be a problem with the rear wheel bearings? This is the only other thing I know is wrong (they need to be replaced), but the noise from that hasnt gotten significantly worse over the last few months.

Grateful for any suggestions.

[phenobarb1]

Well, it definitely doesn't have anything to do with the rear wheel bearings.

Sounds like an electrical issue, where some connection or wiring is losing contact when you go over bumps. Was the car running fine, or at least not having this particular problem, before you replaced the relay?

[jdusty4]

Thanks for the response - before I replaced the relay, I was having a similar but distinct problem, where under acceleration the car would occasionally stutter. It "felt" different, though - this problem is more a sudden loss of power, whereas that was more of a lack of throttle response. Replacing the relay seemed to fix the previous problem (I forgot to mention I also had the main relay replaced).

Last night I was driving up a hill, hit a pothole, and the engine died completely - rpms went immediately to zero, although all gauges were functioning. I could not restart the engine - it cranked fine, etc, but would not start. I also noticed, while listening to the stereo and waiting for a tow, that the left speakers (front and back) are out - I realized this has been the case for probably about a week.

I left it at a mechanic and mentioned that I thought it might be electrical - we'll see what they say, I will update here.

[ak-]

Bad/loose ground wire?