BMW Z4 Running in Limp Mode: Power Loss & CEL Issue

Hey there! I had similar issues with my 2007 BMW Z3 last month. The symptoms were exactly like yours, check engine light, drop in power, and the car going into limp mode. My exhaust had developed a crack near the manifold, which was causing incorrect readings from the temp sensor. The garage found the leak during a smoke test. They had to replace a section of the exhaust pipe and the temperature sensor as it was damaged from excessive heat exposure. It was quite a serious issue since the leak was allowing exhaust fumes to enter areas they shouldn't, plus the engine wasn't running efficiently. Not something you want to leave unfixed, as it could lead to more expensive problems down the line. The repair wasn't a quick fix, took them about a day to complete the work. Since then, the car's been running perfectly, back to its normal power and fuel consumption. Make sure you get it checked by someone who specializes in BMWs, as these issues can be tricky to diagnose correctly. Hope this helps.

Thanks for sharing your experience! It does sound pretty similar to what I went through. Good to hear you got it sorted. Did you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up? Always helps to know what to expect down the road with these repairs.

Hey again! Happy to give you an update! The total repair came to 265 € for fixing the leak in the exhaust system. You'll be glad to know that after getting it sorted, I haven't had a single problem with the car. The faulty exhaust temperature sensor was definitely the culprit, just like I suspected. It's been running like a dream since the repair, no more check engine lights, power's back to normal, and fuel consumption is much better. Honestly, it feels like a different car! The engine's purring along nicely, and I'm getting that responsiveness back that we all love about these BMWs. I know these repairs can seem expensive at first, but trust me, it's worth getting it done properly. Better to fix it now than let it develop into something worse. If you're still looking for a mechanic, just make sure they've got solid experience with BMW systems, it makes all the difference. Let me know if you end up getting yours fixed. Would be interesting to hear if you had the same underlying issue!

Thanks so much for the detailed follow-up! Just got back from the mechanic yesterday actually. You were spot on about getting it checked by BMW specialists, made all the difference. My situation turned out pretty similar, though my repair was a bit pricier at around 320 € because they had to replace some additional sensors. But what a difference! Took it for a drive this morning and it's like having my old car back. The power's restored, no more check engine light, and it's drinking way less fuel. Guess we both learned the hard way about not putting off these kinds of repairs! Really appreciate you sharing your experience, helped me feel more confident about what needed to be done. Funny thing is, my mechanic mentioned seeing quite a few Z4s with similar issues. At least now I know what to look out for if it ever happens again. Fingers crossed we both stay problem-free for a while! Thanks again for all your help!