BMW Z4 Throttle Woes: Limp Mode and Power Loss Mystery

Hey there! Had a similar issue with my 2013 BMW M3 last summer. The symptoms you're describing match exactly what I experienced, unusual power loss, unresponsive accelerator, and that annoying limp mode. Turned out my accelerator pedal module was failing, and there were some issues with the electronics inside it. Got it diagnosed at a shop that specializes in German cars. The tech showed me how the throttle position sensor was sending irregular signals to the ECU. It wasn't just a simple throttle body cleaning job, had to replace the entire pedal module and reprogram the system. It was a serious repair since it's a safety-critical component. The car was undrivable for a while as the parts had to be ordered. My advice would be to get it checked specifically for the accelerator pedal module and throttle position sensor. Ask the mechanic to show you the diagnostic readings, they should be able to see the irregular voltage patterns if that's indeed the issue. Worth mentioning that after the fix, the car's been running perfectly with no more power issues or limp mode episodes.

Hey, thanks for sharing your experience! That's super helpful as it sounds exactly like what I'm dealing with. Just wondering, do you remember roughly how much you ended up paying for the whole repair job? Also, has everything stayed good with your car since then, or have you noticed any other quirks pop up? Trying to get an idea of what I'm in for here.

Hey again! Yeah, I remember exactly what it cost me, just had it fixed a while back. The total bill came to 265 € for the accelerator pedal module replacement. Honestly, it was worth every penny because the car's been running like a dream since then. No more of those scary power drops or limp mode episodes! The throttle valve issue got sorted during the same repair, and it's made a massive difference. The idle is now super smooth, and the throttle response is back to being crisp and immediate, just like how a BMW should feel. Haven't had a single problem since the fix, and it's been such a relief not having to worry every time I press the accelerator. One piece of advice though, make sure they do a proper diagnostic check and reset all the error codes after the repair. That's what my mechanic did, and I think it helped ensure everything was properly calibrated. Trust me, once you get it sorted, you'll feel like you've got a completely different car. Let me know how it goes with yours!

Thanks a bunch for all that detail! Just wanted to update you all on what happened with my Z4. Finally got the courage to take it to a mechanic last week. Turned out you were spot on, it was the accelerator pedal module causing all the trouble. The mechanic showed me the diagnostic readings, and they were all over the place! The repair cost me a bit more than yours, around 320 € including labor, but honestly, it was totally worth it. Had my first proper drive yesterday and what a difference! No more unusual power drops, no more check engine light, and the idle's perfect now. The car feels like new again. The funny part was watching the mechanic's face when he first tried to drive it into the workshop, the car went into limp mode right then! At least it proved my point. He was actually really good about explaining everything and showing me the faulty parts. Really appreciate everyone's help here, saved me from a lot more headaches and probably some money too by knowing exactly what to look for!