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LenaB20

BMW M3 Rough Running & Stalling: Injector Warning Signs

Stalling while idling

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Loss of engine power

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Black smoke from exhaust on acceleration

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Poor fuel economy

Hey there! Looking for advice about my 2019 BMW M3 (137,933 KM). The car's been acting up lately, getting jerky during drives, drinking way more fuel than usual, and losing power out of nowhere. What's really concerning is the engine stalling when idle and the smoke coming out when I accelerate. I'm thinking it might be the injection system, but after a bad experience with my last mechanic, I want to hear from others who've dealt with similar symptoms. Anyone faced this before? Where did you get it fixed and how much did it set you back? Thanks in advance!

4 comment(s)


MoriSchmidt

I faced similar issues with my 2016 BMW M4 last year. The symptoms you're describing match what I experienced, rough idle, power loss, and excessive fuel consumption. The problem turned out to be faulty fuel injectors and worn-out ignition coils. My car was misfiring because the injectors weren't spraying fuel properly, and the connection cables to the injectors were corroded. Had to replace three injectors and all ignition coils. It was definitely a serious issue that needed immediate attention, driving with faulty injectors can damage your catalytic converter and engine in the long run. I got it fixed at an independent BMW specialist workshop since my warranty had expired. The repair took about a day and a half. If you're getting smoke during acceleration, I'd suggest getting it checked soon. These symptoms usually don't improve on their own and could lead to bigger problems if left unattended.

LenaB20 (Author)

Hey, thanks for sharing your experience, it's super helpful! What you described sounds exactly like what I'm dealing with right now. I'll definitely look into the injectors and ignition coils. Just wondering, do you remember roughly how much the repairs cost you? And has everything been running smoothly since the fix, or have you noticed any other issues pop up? Would really appreciate any extra insight. Thanks again for the advice about getting it checked quickly. You're right, better safe than sorry with these things!

MoriSchmidt

Hey there! Just wanted to follow up on your questions. Great news, my car's been running like a dream since I got it fixed! The mechanic found it was indeed the injection system causing all that trouble, but fortunately, it wasn't as expensive as I initially feared. Turned out the main issue was just a faulty cable connection to one of the injectors that needed fixing, ended up costing me 95 € for the repair. Much cheaper than I expected, especially since I was worried I'd need to replace multiple injectors like I mentioned before! The car's performance is back to normal now, no more jerky movements, weird smoke, or excessive fuel consumption. Haven't had a single problem since the repair. My advice would definitely be to get yours checked out soon. Sometimes these things can be simple fixes like mine turned out to be, rather than major repairs. Better to catch it early before it causes any bigger issues! Let me know how you get on with yours, always interested to hear how these things work out.

LenaB20 (Author)

Just got back from the mechanic and wanted to update you. You were spot on about getting it checked early! Turns out I had a similar issue, faulty wiring in the injection system plus one bad injector. The mechanic managed to sort it out pretty quickly. The whole thing set me back about €450, including parts and labor. A bit more than your repair cost, but still way better than having to replace the entire system. The best part? My car's running perfectly now, no more stalling, no weird smoke, and the fuel consumption is back to normal. Really appreciate you sharing your experience. It definitely helped me make the right call getting it checked out straight away instead of waiting for things to get worse. Feels great to have my BMW running smoothly again! The mechanic also gave it a full inspection while it was there and everything else looks good. Guess sometimes these problems turn out simpler than we expect. Thanks again for all your help!

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