BMW Z3 Fuel Regulator Woes: Common Fix Revealed

Hey there! I experienced similar symptoms with my 2003 BMW Z4 last year. Initially thought it was something minor, but it turned out to be a high-pressure fuel pump failure. The symptoms matched yours exactly, rough idle, power loss, and that annoying check engine light. I had the same hesitation about mechanics, but found a good independent BMW specialist. The fuel pump needed complete replacement, it's a serious job as it's a critical component for proper fuel delivery to the engine. The repair took about a day and a half due to some additional testing they needed to do. The symptoms you're describing are classic signs of fuel delivery issues, and given the mileage on your Z3, it wouldn't be surprising if it's the fuel pump. My advice would be to get it checked soon, driving with a failing fuel pump can potentially damage other components. Just a heads up, when they diagnosed mine, they found some worn fuel lines too, so you might want to have those checked while they're at it. Hope this helps!

Thanks for sharing your experience! I'm actually considering taking my Z3 to a specialist too. That's interesting about the fuel pump, good to know it might not just be the regulator. Sounds like you got it sorted properly. Quick question, do you remember roughly how much the whole repair set you back? Also, has everything been running smoothly since the fix? Just trying to get an idea of what I might be in for.

Hey again! Absolutely happy to help! Yes, everything's been running like a dream since I got it fixed. The specialist I found really knew their stuff, they spotted that both the high-pressure pump and fuel volume regulator were causing the issues. Got both sorted and the car's been purring like a kitten ever since. The total damage was 1510 € for the pump replacement, which honestly wasn't as bad as I was fearing given it's a BMW we're talking about! Worth every penny though, no more stalling, power loss, or that super annoying check engine light. The car feels like new again, seriously. The fuel economy's actually better now too, which is a nice bonus. I'd definitely recommend getting yours checked out sooner rather than later. These issues tend to get worse (and more expensive) if you leave them too long. Plus, driving around with dodgy fuel delivery isn't great for other engine components. Let me know how you get on with yours, always interested to hear how fellow BMW owners sort their issues out!

Thanks for all the detailed info! Just got back from a BMW specialist actually. You were spot on, it was indeed the fuel pump causing all the drama. Had it replaced yesterday and what a difference! The car's running so much smoother now. The repair cost was pretty close to what you mentioned. Ended up being around 1600 € with some additional work they found needed doing. Actually feeling pretty relieved now, was worried it might've been something way more serious. The mechanic was fantastic too, way better than my last experience. They walked me through everything they were doing and even showed me the old pump, it was definitely on its last legs! Like you said, the fuel economy's better now, and that annoying engine light is finally off. Really glad I reached out here and got your advice. Sometimes it's just good to hear from someone who's been through the same thing. Time to enjoy my Z3 properly again!