BMW 1 Series Diesel Stalling: Air Pump Issues

Hey there! I have some experience working on cars and faced a really similar issue with my 2013 BMW 3 Series diesel last year. The symptoms you're describing ring a bell, had the same jerking and stalling problems with my car. Turned out the hose connection between the pump and valve was damaged, causing those exact symptoms you mentioned. Took it to my regular workshop and they spotted it pretty quickly. The fix cost me around 175 Euro, but it solved the problem completely. Since yours is a 1 Series from the same family, it could be the same issue, but I'd need to know a few things first: Does the engine light come on right after starting the car? And have you noticed any unusual sounds from the engine bay when starting up? Just to add, if it is the same problem, it's not a major repair but definitely needs attention soon to prevent any further damage to the system.

Thanks for sharing your experience! This definitely sounds similar to what I'm dealing with. To answer your questions, yes, the check engine light comes on almost immediately after starting, and there's a distinct whining noise from the engine bay during cold starts. I just had my regular service about 2 months ago at 112,194 KM, and everything was fine then. So this issue is pretty recent. I'm hoping it's just the hose connection like in your case, that sounds like a much better scenario than having to replace the entire pump system. Did your car also have that whining noise? I'm thinking of taking it to the workshop this week before it potentially gets worse.

Hey again! Yeah, that whining noise is exactly what I had with my BMW too! It's actually a pretty telltale sign of the hose connection problem I mentioned before. Mine made this really annoying high-pitched sound, especially during those cold morning starts. Given what you're describing, the immediate check engine light and that distinct whining, I'm even more convinced it's the same issue I dealt with. It's good you're planning to get it checked soon because I learned the hard way that waiting too long can lead to other problems. Just one heads up though, when I finally got mine fixed, they found that the connection point had some minor corrosion too. The mechanic cleaned that up while replacing the hose, which probably helped prevent the issue from coming back. Might be worth asking them to check for that when they look at yours. The good news is that my car has been running perfectly since the repair, no more jerking, stalling, or weird noises. Oh, and if they quote you way more than what I paid, maybe get a second opinion. Some places try to push for a full pump replacement when it's really just the connection that needs fixing. Keep us posted on what you find out! Always curious to hear if these similar cases end up having the same solution.

Thanks so much for all the detailed feedback! It's really reassuring to hear that you dealt with such a similar issue and got it fixed without too much hassle. The corrosion tip is especially helpful, I'll definitely mention that to the mechanic when I take it in. I've actually just booked an appointment for tomorrow morning. After hearing about your experience, I feel much more confident about what to expect and what to ask them to check. The fact that your repair cost was reasonable and solved all the problems completely is really encouraging. I'll make sure to specifically ask them to inspect the hose connection and check for any corrosion before they suggest replacing any major parts. Hopefully, I can avoid an unnecessary full pump replacement like you mentioned. Thanks again for taking the time to share your experience, it's been super helpful in understanding what I might be dealing with. I'll update the thread once I get the diagnosis and repair done. Fingers crossed it's as straightforward as your case was!