BMW Z3 Idle Woes: Fuel System or Injector Issue?

My 2004 BMW Z4 had almost identical symptoms last month. I feel your pain. After taking it to the garage, they diagnosed dirty/clogged fuel injectors, exactly what you're suspecting. The carbon deposits were preventing proper fuel atomization. The fix involved a complete fuel injection cleaning service and replacing two injectors that were beyond salvaging. Wasn't a quick fix, took about two days in the shop, but it solved all the symptoms, rough idle, poor acceleration, high fuel consumption, and unusual stalling. While it's not a catastrophic issue if addressed promptly, ignoring it can lead to more severe engine damage. The injectors are crucial for proper fuel delivery and engine performance. Honestly, with those symptoms on a Z3, I'd strongly recommend getting it checked by a certified BMW specialist rather than a general mechanic. You want someone who knows these engines inside out.

Thanks so much for sharing your experience. The fuel injector issue sounds exactly like what I'm dealing with. Getting them professionally cleaned seems like the way to go. Do you remember roughly how much the whole service set you back? Also, has everything been running smoothly since the fix, or have you noticed any other issues pop up? Really appreciate your help!

Hey there again! Just wanted to follow up, yeah, I got the injection system sorted out last month, and what a difference! The mechanic confirmed it was a defective injector nozzle, just like I thought. Had to shell out 515 € for the fix, which included cleaning the dirty injection valve, but honestly, it was worth every penny. Since the repair, my Z4's running like a dream, all those annoying issues are completely gone. No more rough starts, no stalling, and the fuel consumption is back to normal. The engine's got its zip back too, which is what these cars are all about, right? I was actually worried there might be some lingering problems after the fix, but it's been smooth sailing. The car feels just like it did when I first got it. Really happy I didn't wait any longer to get it sorted, these things can get worse if you let them drag on. If you're still on the fence about getting yours fixed, I'd say go for it. Better to deal with it now than wait for bigger problems to develop.

Really glad I reached out here! After your messages, I bit the bullet and took my Z3 to a certified BMW mechanic last week. You were spot on, it was definitely the fuel injectors causing all the trouble. The mechanic did a thorough cleaning and ended up replacing three injectors that were completely shot. The bill came to about €600, which was actually less than I was expecting after your experience. Got the car back yesterday, and wow, what a difference! It's running smooth as silk now, starts right up, and the power's back to where it should be. Funny thing is, I didn't realize how bad it had gotten until I felt how it's supposed to run. No more embarrassing stalls at traffic lights or that awful choppy idle. I should've done this months ago instead of putting it off. Thanks again for pushing me to get it properly checked out. Sometimes you just need someone who's been through it to point you in the right direction!