BMW Diesel Won't Start: AdBlue Tank Empty Warning

Hey there! I had a similar issue with my 2012 BMW 3 Series 320d last winter. The symptoms you're describing sound very familiar. Initially thought it was just an empty AdBlue tank, but turned out the dosing unit wasn't delivering the fluid properly to the SCR system. The connections between the tank and dosing unit were corroded, and the pump wasn't functioning correctly. Had to get the entire delivery system replaced, including the pump and several sensors. It was quite a serious repair since the car wouldn't run without a properly functioning AdBlue system. Even though the tank was nearly full, the system wasn't detecting or delivering the fluid properly. The warning messages kept coming up until the car eventually refused to start, exactly like your situation. If I were you, I'd get it checked at a different workshop that specializes in diesel systems. These AdBlue issues aren't something you want to ignore as they can lead to bigger problems with the SCR system. Just filling up the tank probably won't solve your problem if there's an underlying delivery system issue. Hope this helps.

Thanks for sharing your experience! That definitely sounds like what I'm going through with my BMW. Really helpful to know about the potential issues with the delivery system, I hadn't even thought about corrosion being the culprit. Hey, do you remember roughly how much you ended up paying for the repairs? Also, has everything been running smoothly since you got it fixed, or have you had any other AdBlue-related problems pop up?

Hey again! Happy to give you an update! Since my last post, I actually got the issue fixed, spent exactly 250 € to repair the AdBlue delivery system. The problem was exactly what I suspected, the output from the tank to the dosing unit was defective. The good news is that since the repair, my 320d has been running like a dream! Not a single AdBlue warning message in sight. The mechanic did a thorough job cleaning and replacing the corroded parts, and honestly, it was worth every penny. The car feels much more responsive now, and I'm getting better fuel economy too. I know you were worried about going back to your mechanic, and I totally get that. Finding a trustworthy specialist who knows their way around these diesel systems really makes all the difference. If you're still having issues, I'd definitely recommend getting it looked at by someone who specializes in BMW diesels, these AdBlue systems can be quite tricky to diagnose correctly. Let me know how you get on with yours! Always happy to share more details about my experience if you need them.

Thanks so much for all the detailed info! Just wanted to update everyone, I bit the bullet and took my car to a different mechanic yesterday. You were spot on about the delivery system being the culprit. They found corroded connections and a faulty pump, pretty much exactly what you described. The repair cost me a bit more than yours, around 300, but they also cleaned out the entire system and replaced some worn-out sensors. Got the car back today and it's running perfectly! No more error messages, and the engine feels much smoother. Really glad I didn't just try to fill up the AdBlue tank and hope for the best. Having a proper diagnosis and repair done was definitely the right call. The new mechanic was great too, showed me all the damaged parts and explained everything clearly. Thanks again for sharing your experience, it gave me the confidence to get this sorted properly instead of taking it back to my old mechanic. What a relief to have this fixed!