BMW 8 Diesel Glow Plug Issues: Cold Start Nightmare

Hey there! I had similar issues with my 2019 BMW 7 Series diesel last winter. I'd say I have some experience working with cars, but I usually leave the complex stuff to professionals. The symptoms you're describing sound exactly like what I dealt with. The preheating light wouldn't go away, and starting the car was getting worse each day. My local workshop confirmed it was indeed a faulty glow plug, they had to replace one of them. The whole thing cost me around 440 Euro, but it solved the problem completely. Before jumping to conclusions though, could you share which engine variant you have and if you're getting any specific error codes? Also, how long have you noticed the battery drain? This info would help determine if you're facing the exact same issue. The 8 Series is basically a cousin to my 7 Series, so I'd be happy to share more details about my repair experience if your symptoms match up.

Thanks for sharing your experience! Mine's definitely showing the same symptoms you described. I've got the straight-six diesel engine, and I'm getting the P0671 error code. Been noticing the battery drain for about two weeks now. Had my latest service just 3,000 km ago at 147,887 km, so this issue is pretty recent. I'll probably take it to a workshop then, sounds like it needs professional attention. The cold starts are getting really annoying! Did you notice any improvement in fuel consumption after your repair? Just curious if this might have been affecting efficiency without me realizing it.

Hey again! Yes, I remember dealing with this exact same headache with my 7 Series. Actually, funny you should ask about the fuel consumption, I definitely noticed an improvement after getting the glow plug replaced. Looking back, I reckon I was losing about 0.5-0.7L/100km without even realizing it. The engine just runs so much smoother now, especially during those cold starts. With the P0671 code, you're absolutely spot-on about getting it checked professionally. Mine showed the same code, and waiting too long can potentially cause more issues down the line. Just a heads up, when I got mine fixed, they actually recommended checking all the glow plugs while they were at it. Ended up replacing two instead of just one, but it was worth it for the peace of mind. Since you mentioned you're at 147,887 km, it's about the same mileage where mine started acting up too. These straight-six diesels are generally bulletproof, but the glow plugs are kind of their weak spot, especially after the 140,000 km mark. Quick tip from my experience, if you're planning to get it fixed, try to do it sooner rather than later. The constant battery drain isn't doing your starter motor any favors. Trust me, I learned that the hard way!

I'll wrap this up Thanks for all that detailed info, really helpful! The mileage similarity definitely makes me feel better about this being a common issue rather than something weird with my car. I'll get it booked in this week then, and I'll definitely take your advice about checking all the glow plugs while they're at it. Better to sort everything at once than have to go back again. The tip about the starter motor is particularly good to know. I've already noticed the starts getting a bit rougher, so I won't delay this any longer. Plus, if I can get better fuel economy out of this, that's a nice bonus! Really appreciate you taking the time to share your experience, it's made me feel much more confident about what I'm dealing with. Will probably get this sorted by early next week. Thanks again for all the advice!