BMW M4 Fuel Injector Drama: Community Help Needed

Hey there! I had very similar issues with my 2014 BMW M3 last year. The symptoms matched yours exactly, rough idle, hard starts, and increased fuel consumption. Turned out to be dirty fuel injectors, which was causing incomplete fuel atomization. Got it diagnosed at a certified shop. They had to remove and ultrasonically clean all injectors, plus replace two that were beyond saving. It was a serious job that took about 6 hours of labor. The car's been running like new since then, smooth idle, quick starts, and back to normal fuel consumption. Just make sure you go to a shop that specializes in direct injection engines, as these systems are quite complex. They'll need proper diagnostic equipment to test injector spray patterns and flow rates. After fixing the injectors, I've started using better quality fuel and fuel system cleaners every few months as preventive maintenance. Haven't had any issues since. Hope this helps with your decision making.

Thanks for sharing your experience! That's exactly what I needed to hear. Can I ask how much you ended up paying for the whole job? And has everything been running smoothly since the repair, or have you noticed any other issues pop up? Just trying to get a better idea of what I might be looking at cost-wise, and whether I should prepare for any other potential problems down the line. Really appreciate your help with this!

Hey again! Yeah, no problem at all! I actually just got everything sorted out last week. The total bill came to 515 € for fixing the injection valve that was giving me grief. Turns out the nozzle was completely shot, which explained all those annoying symptoms we discussed. Since the repair, my M3's running like an absolute dream, way better than before! No more of that frustrating rough idle or those scary stalling moments. Starting up is smooth as butter now, and my fuel consumption's back to normal. Seriously, it's like driving a different car. I'm kicking myself for not getting it checked sooner, but you know how it is when you've had bad experiences with mechanics before. The specialist I found really knew their stuff with direct injection systems though. They showed me the faulty parts and explained everything clearly. If you're still on the fence about getting yours looked at, I'd say just go for it. These injection issues don't fix themselves, and waiting usually just leads to more problems. Plus, the peace of mind is totally worth it. Let me know if you need any other info!

Thanks so much for all the details! You convinced me to bite the bullet and get it checked out. Just got back from the mechanic yesterday, and wow, what a difference! Turned out three of my injectors were pretty much done for. The mechanic showed me the buildup, it was nasty stuff. Bill came to about 750 € with parts and labor, bit more than yours but still worth every penny. They had to replace those three injectors completely and clean the fourth one. The car feels completely transformed now. Started right up this morning, smooth as silk, and the engine's purring like it should. No more of that annoying rough idle or stalling. Even my fuel consumption has dropped back to normal levels. Really glad I listened to your advice about finding a specialist. The guy I went to actually took the time to explain everything and show me the problems. Such a different experience from my last mechanic. Thanks again for helping me make the right call on this one!