BMW Z3 Power Loss: IAT Sensor Issue or Something More?

Hey there! I've got some experience with cars, not a pro mechanic but I've dealt with my share of issues. Had a similar problem with my 1998 BMW M3 last year. The symptoms were exactly what you're describing, check engine light and power loss. Took it to my regular workshop and yep, it was the intake air temperature sensor acting up. The fix was pretty straightforward, they replaced the sensor and cleared the codes. Cost me about 155 Euro, which included parts and labor. Car's been running like a charm since then. Before jumping to conclusions though, what codes is your scan showing? Also, have you noticed any other symptoms like rough idling or poor fuel economy? Would help to know these details to be sure we're dealing with the same issue. If it turns out to be the same problem, it's actually a pretty common issue with these older BMWs. Let me know the details and I might be able to share more specific info that could help!

Thanks for sharing your experience! My car's at 82070 KM and just had service last month. The scan's showing P0113 and P0112 codes. And yes, actually noticed the fuel economy getting worse lately, plus some rough idling, especially when cold. Seems like we might be dealing with the same issue. Really appreciate the cost estimate, that's actually less than I was worried it might be. Think I'll get it checked out at the shop this week, hopefully it's just the sensor like in your case. These old Bimmers sure keep us on our toes!

Hey again! Yeah, those P0113 and P0112 codes you mentioned, that's exactly what I was dealing with on my M3! Just confirms what I suspected. The symptoms match up perfectly too, my fuel economy was taking a hit just like yours, and I had that same annoying rough idle, especially during those cold starts. Since I got mine fixed last year, I've actually learned a bit more about this issue. Found out these sensors tend to fail gradually, which explains why the fuel economy gets worse over time. The rough idle happens because the engine management system gets confused by the wrong temperature readings. Quick update on my repair, it's been about 14 months since I got it fixed, and I haven't had a single problem since. The fuel economy went right back to normal, and that annoying rough idle completely disappeared. Just a heads up, when you take it in, make sure they check the wiring connections too. My mechanic showed me that sometimes the problem can be as simple as corroded contacts rather than a completely failed sensor. Might save you some money if that's the case. Let me know how it goes when you get it checked out. Always interested to hear if others have the same experience with these old BMW quirks!

Thanks so much for all this detailed info! Really helpful to hear about your long-term success after the repair. I've actually just called the shop and booked it in for tomorrow morning. Good tip about checking the wiring connections, I'll definitely mention that to them. It's such a relief to hear from someone who's had the exact same codes and symptoms, and got it all sorted. Fingers crossed it'll be just as straightforward for my Z3. Really appreciate you taking the time to share all your experience with this. Will definitely update the thread once I get it fixed to help out anyone else who might run into the same issue with their Bimmer!