BMW X3 Diesel Rough Idle: Common Fuel Heater Issues

Hey there! Had similar issues with my 2006 BMW X5 diesel last winter. Your symptoms sound exactly like what I experienced. In my case, it turned out to be more than just the fuel filter heater, the entire fuel pressure regulator was failing, and there were some bad connections to the fuel heater plug. Fixed it at the garage two months ago. The mechanic first checked the diagnostic codes, then tested the fuel pressure and electrical connections. The regulator needed replacement, and they had to repair some corroded wiring to the heater plug. It was quite a serious job since it affected the entire fuel delivery system. One tip: make sure they check the wiring harness thoroughly. In my case, what seemed like a simple heater issue was actually a combination of problems. The repair took about a day and a half, but it solved the rough idle and cold start issues completely. Fuel consumption went back to normal too. Hope this helps with your decision.

Hey, thanks so much for sharing your experience! That's really helpful info. My issue does sound very similar to what you encountered. I'm actually thinking about getting this fixed soon as it's starting to worry me a bit. Quick question, do you remember roughly how much you ended up paying for the whole repair job? Also, has everything been running smoothly since the fix, or have you noticed any other issues pop up?

Hey again! Good news, I can put your mind at ease! After my previous message, I took my X5 to the mechanic and it turned out to be much simpler than my initial repair. The fuel filter heater issue was just a faulty cable connection, way less complicated than the regulator problem I mentioned before. Only cost me 95 € to fix the cable connection, which was such a relief compared to what I was expecting! My mechanic had it sorted in about an hour. Since then, the car's been running like a dream, no more rough starts in the morning, fuel consumption's back to normal, and that annoying check engine light is finally gone. It's been about three months now and I haven't had a single issue pop up. The idle's smooth as silk and the cold starts are perfect. Honestly, I wish I'd gotten it fixed sooner instead of worrying about it for so long. So yeah, based on your symptoms, you might get lucky like me and just need a simple fix. Worth getting it checked out soon though, better safe than sorry with these diesel engines!

Thanks for the follow-up! Just wanted to let you know I finally got my car checked out yesterday. You were right about getting it fixed sooner rather than later! Turned out my issue was a bit different though. The mechanic found a clogged fuel filter and some dirty injectors. The total bill came to about 200 bucks for parts and labor. Not too bad considering what I was worried it might cost! They cleaned out the whole system and replaced the filter. Took about three hours total, but wow, what a difference! The engine's purring like a kitten now, starts up instantly even in cold weather, and my fuel economy has improved dramatically. After that bad experience with my last mechanic, I'm really glad I asked for advice here. The new guy was super professional and even showed me the old parts to explain what was wrong. Definitely keeping him as my regular mechanic from now on. Thanks again for helping me sort this out, really appreciate you sharing your experience!