BMW M3 Air Suspension Issues, Help Diagnosing Compressor

Hey there! I have some experience working on cars, and I actually faced something similar with my 2005 BMW M5. The symptoms you're describing sound very familiar, I also had issues with uneven ride height and those annoying warning lights. In my case, it turned out to be a faulty wiring connection to the air suspension system. My mechanic found that some cables were corroded and a connector was loose. The fix was relatively straightforward, they replaced the damaged wiring and connector. Cost me around 95 Euro and took about 2 hours of labor. Before jumping to conclusions about the compressor (which would be much more expensive), I'd recommend getting those electrical connections checked first. Could save you a lot of money! Can you share some more details about your car? Like: Have you noticed any unusual noises from the suspension? When did these symptoms first appear? Does the problem get worse in certain weather conditions? BTW, the fact that you're getting reduced engine power along with suspension issues makes me suspect it might be electrical-related, just like mine was.

Yeah, just had my latest service done and at 29448 KM, the car is actually doing pretty well overall aside from this issue. The electrical connections make a lot of sense, I've been hearing a slight clicking sound from the front right when going over bumps. It started about a week ago, and seems worse in damp weather. No strange noises from the compressor itself though. Been keeping a close eye on the suspension behavior since it first happened, and I noticed the front passenger side seems to drop more than the others when parked overnight. Really appreciate the tip about checking the wiring first, was dreading a full compressor replacement! Think I'll get those connections checked out ASAP before throwing parts at the problem. Just hoping it's as straightforward as your fix was!

Hey again! Thanks for the additional details about your M3. Those symptoms you're describing, especially that clicking sound and the overnight drop on the passenger side, are really similar to what I experienced with my M5. The overnight drop is particularly telling. When I had my issue, the corroded wiring was actually preventing the system from maintaining proper pressure. The damp weather connection makes total sense too, that's exactly when my electrical gremlins would act up the most. Just a heads up from my experience, when my mechanic did the repair, they found that the wire insulation had worn through in a spot where it was rubbing against a suspension component. Might be worth having them check your wire routing while they're in there. That clicking sound you mentioned could be related to this. After my repair, it took about 2-3 cycles of the suspension system to fully normalize everything. Don't panic if it doesn't immediately fix itself after they repair the wiring. Mine took a short drive around to fully sort itself out. Keep me posted on what they find. If it does turn out to be wiring like mine was, you'll be back to normal in no time. And hey, way better than shelling out for a new compressor!

Thanks so much for sharing your experience! Just got back from the mechanic and you were spot on, they found some damaged wiring near the front passenger wheel well. Looks like it had been rubbing against the suspension component, just like you mentioned. The repair was pretty reasonable, about 2 hours of labor plus parts. They also rerouted the wiring to prevent future issues. Took the car for a good drive afterward and you were right again, it took a few suspension cycles, but everything's working perfectly now. No more clicking, no more uneven settling, and all the warning lights are gone! Really glad I didn't jump straight to replacing the compressor. Would've spent way more money for no reason. The electrical issue makes total sense with all the symptoms I was seeing, especially how it got worse in damp weather. Can't thank you enough for pointing me in the right direction. Saved me a bunch of time and money! Going to keep an eye on it for the next few weeks, but feeling pretty confident this was the fix I needed.