BMW Diesel Fuel Heater Symptoms Baffle Owner

Had the exact same symptoms on my 2015 BMW 5 Series diesel at 80k km. Rough idle, terrible cold starts, and the fuel consumption went through the roof. Diagnostic showed the fuel filter heater connector was corroded and had a loose connection. The wiring harness needed repair too since there was some damage from moisture. Not a complex fix, but it required specific testing equipment to ensure proper voltage. Got it sorted at the garage in about 4 hours. The technician found that water had gotten into the connector housing, causing the corrosion. They replaced the entire connector assembly and sealed it properly. The car's been running like new since then, no more cold start issues or rough idle. This isn't a serious problem if caught early, but ignoring it could lead to bigger fuel system issues. Just make sure whoever works on it knows BMW diesel systems well. Hope this helps with your decision!

Hey, thanks for sharing your experience! Sounds exactly like what I'm dealing with. Really helpful to know it was the connector and wiring harness in your case. Would you mind sharing how much the repair set you back? Also, has everything stayed running smooth since the fix, or have you noticed any other issues pop up? Just want to make sure I'm prepared for what's ahead. Thanks!

Hey again! Happy to update you on my experience. I went ahead and got it fixed at the mechanic's last week, total bill came to 95 € for sorting out the faulty cable and plug connection on the fuel filter heater. Honestly, it was money well spent because my 5 Series is running like a champ now! Since the repair, all those annoying issues have completely disappeared. No more rough starts in the morning, the idle's smooth as silk, and the fuel consumption's back to normal. I'm pretty relieved it wasn't anything more serious. Haven't had a single problem since the fix, which is brilliant. The mechanic mentioned it's actually quite a common issue with these diesels, just needs someone who knows what they're doing to diagnose and fix it properly. I reckon you're dealing with the same thing based on your symptoms. Get it sorted sooner rather than later and you should be all good. Let me know how you get on!

Thanks for the update! Actually, I just got back from the mechanic today. Took your advice and found a BMW specialist who knew their stuff. What a difference! Had the same repair done, fuel filter heater connection and wiring sorted out. Mine was a bit pricier at 120 € since they had to replace a few extra bits, but totally worth it. Started up this morning and wow, feels like I've got a new car! No more sluggish starts, engine's purring at idle, and the power's back. Really glad I didn't put it off any longer. The mechanic even showed me the corroded parts they replaced, pretty nasty stuff. Really appreciate you sharing your experience. Helped me avoid what could've been a much bigger headache down the road. Think I've found my new go-to mechanic too, they really knew their way around these BMWs. Thanks again for pointing me in the right direction!