BMW Diesel Preheating Light Stuck? Glow Plug Issues Inside

Hey there! I had a similar issue with my 2011 BMW 3 Series diesel last winter. I have some experience working on cars, mostly basic maintenance stuff. I noticed exactly the same symptoms on my car, preheating light staying on, tough cold starts, and battery strain. Took it to my regular workshop and, yep, it was a faulty glow plug. They had to replace one glow plug and ended up costing me around 440 Euro for parts and labor. Car's been running perfectly since then. Before you move forward though, could you share: Any specific error codes you're getting? Does it happen only during cold starts or all the time? Have you noticed any smoke from the exhaust? Just want to make sure it's the same issue before you spend money on repairs. These BMW diesels are great but can be tricky with their glow plug systems.

Thanks for the detailed response! I got the error code P0670. The starting issue only happens during cold starts, and there's no unusual smoke from the exhaust. Last service was done three months ago at 14766 KM, and everything else seems to run fine. Really appreciate your input about the glow plug, sounds exactly like what I'm experiencing. I'll get it checked out by my mechanic. Just wanted to make sure I'm not overlooking something obvious before taking it in. Did your BMW throw any other warning lights when you had this issue?

Hey again! Glad I could help earlier. When I had the glow plug issue with my BMW, I actually did get the P0670 code too, it's pretty specific to the glow plug control module circuit. And yeah, now that you mention it, I didn't get any other warning lights either, just that stubborn preheating lamp that wouldn't turn off. Your symptoms are matching up exactly with what I experienced, the cold start issues without any weird smoke is pretty much a telltale sign. Since you mentioned your recent service, that's good to know, my issue popped up about 4 months after a regular service too. One thing I forgot to mention in my first reply, after they replaced the faulty glow plug, my mechanic recommended checking all the others too. Apparently, when one goes bad, the others might not be far behind. I decided to just replace all of them since I was already paying for the labor, and honestly, it was worth the extra cost for the peace of mind. The fact that everything else runs fine is another indicator that we're dealing with the same issue. These BMWs are pretty good at isolating problems, so when it's just the cold start and preheating light, it's usually not something more serious. Just make sure your mechanic clears the error code after the repair, mine forgot initially and I had to go back.

Thanks so much for all this information! I really appreciate you sharing your experience, especially about getting all the glow plugs checked. That's actually a really smart suggestion, I'd rather fix everything while they're already working on it than have to deal with this again in a few months. I'll definitely mention the P0670 code to my mechanic and ask about checking all the glow plugs. Good tip about making sure they clear the error code too, I'll keep that in mind. Your detailed explanation has made me feel much better about the whole situation. At least I know what I'm likely dealing with and roughly what to expect cost-wise. Going to book it in tomorrow morning and hopefully get this sorted out before it gets any worse. Really appreciate you taking the time to share your experience, it's exactly what I needed to hear!