BMW Z3 Check Engine + Jerky Acceleration, Need Help

Hey there! I had similar issues with my 2005 BMW Z4 last year. The symptoms you're describing match what I experienced, rough running, jerking, and limp mode. Turned out I had a significant exhaust leak at the manifold, which was causing incorrect readings in the oxygen sensors. The fix required replacing the exhaust manifold gasket and two damaged oxygen sensors. It was pretty serious since the leak was affecting engine performance and could've led to bigger problems if left unchecked. The mechanic showed me where the old gasket had completely deteriorated, letting exhaust gases escape. The repair took about a day and a half at the shop, but it solved the problem completely. Car's been running smooth since then. I'd suggest getting it checked soon, these symptoms typically don't improve on their own. Best of luck with yours!

Thanks so much for sharing your experience! That's really helpful as it sounds exactly like what I'm dealing with. Quick question, do you remember roughly how much you ended up paying for the whole repair job? Also, has everything stayed running smoothly since then, or have you noticed any other issues popping up? Would be great to know what to expect.

Hey again! Happy to give you an update! The repair job ended up costing me 265 € to fix the exhaust leak, and I'm glad to report it was totally worth every penny. The car's been running like a dream since I got it sorted, no more uneven running or jerking issues at all. My mechanic did a thorough job with the exhaust system, and honestly, the difference in how the car runs now is like night and day. The engine's smooth as silk, and that annoying check engine light hasn't come back on. No other problems have shown up either, which is a huge relief. I know you mentioned being hesitant about mechanics after a bad experience, but getting this fixed properly really is the way to go. The symptoms you're describing are pretty much identical to what I dealt with, so I reckon you're looking at a similar repair. Better to get it sorted sooner rather than waiting for it to potentially get worse. Let me know how it goes if you decide to get it checked out!

Thanks for all the detailed info! Just wanted to update you, I actually bit the bullet and took it to a new mechanic yesterday. You were spot on about the exhaust leak! My repair was a bit pricier at 340 € since they found a few other minor issues, but I'm so glad I got it done. The funny part was when the mechanic showed me the old gasket, it was basically in pieces! Can't believe I drove around like that for so long. Theyaged to fix everything in one day, and I picked up the car this afternoon. The difference is incredible, no more jerking, no more check engine light, and it's running super smooth. Really appreciate you sharing your experience, it gave me the confidence to get it sorted instead of putting it off. And you're right, finding a good mechanic makes all the difference. This new place was great, they explained everything clearly and even showed me the damaged parts. Thanks again for the help!