BMW 5 Series Diesel: Jerky Acceleration & Power Loss Help

Hey there! I have some experience working on cars, and this sounds very familiar. I had a similar issue with my 2004 BMW 3 Series diesel (pretty much the same engine family as your 5 series). Mine was also jerking and losing power, with that typical diesel smell you mentioned. Turned out it was exactly what you suspect, a scorched intake manifold that was leaking. The symptoms match perfectly. My trusted mechanic found cracks in the manifold where it had gotten too hot. The whole repair, including parts and labor, set me back about 1180 Euro, but it fixed the problem completely. Before I say more, what codes is your check engine light showing? Also, have you noticed any black smoke from the exhaust? These details would help confirm if we're dealing with the same issue. By the way, when I had this fixed on my 3 Series, I also had them check the EGR system since these issues sometimes go hand in hand. Might be worth looking into for your case too.

Thanks for sharing your experience! I've got 95013 KM on the clock, and you're spot on, these symptoms do sound very similar to what you described. The check engine light's throwing code P1456 (which points to the intake system), and yes, I've been seeing some black smoke, especially when accelerating. Good call on checking the EGR system too. Did you notice any improvement in fuel economy after your repair? I'm currently burning through fuel like crazy, which I'm guessing isn't helping my wallet! Let me know if your mechanic mentioned any preventive measures to avoid this happening again. Really appreciate the help!

Hey again! Absolutely, I remember my fuel economy was terrible when I had this issue, I was practically watching the fuel gauge drop in real time! After getting the intake manifold replaced on my BMW, I saw a massive improvement in fuel consumption. It went from being a fuel-guzzling nightmare back to normal pretty quickly. That P1456 code is exactly what I got too. Interesting that your mileage is 95K, mine was around 98K when it happened, so it seems like a common failure point for these engines. About preventing it from happening again, my mechanic actually gave me some solid advice. He recommended regular carbon cleaning services every 50K kilometers and said to avoid too many short trips where the engine doesn't get fully warm. I've been following that advice for the past year, and so far, so good. Also, while they had everything apart, I had them do a thorough cleaning of the EGR valve. It was pretty gunked up, which apparently is common on these diesels. Might be worth considering since they'll need to access that area anyway. I've put another 40K on the clock since the repair, and everything's still running smooth. Just keep an eye on that engine temp gauge, apparently, excessive heat can speed up the manifold deterioration. Let me know how the repair goes!

Thanks so much for all that detailed info! Really helpful to know about the carbon cleaning schedule, I had no idea that short trips could contribute to this problem. I'll definitely get both the manifold and EGR valve checked out. Just booked it in with my mechanic for next week. He's going to do the full works including that thorough EGR cleaning you mentioned. The fuel consumption thing was driving me crazy, so I'm relieved to hear it went back to normal after your fix. 40K kilometers without issues after the repair sounds promising! I've been stressing about whether this would be a recurring problem, but it seems like with proper maintenance it should be fine. I'll make sure to keep an eye on that temp gauge too. Thanks again for taking the time to share your experience. It's given me a much clearer picture of what I'm dealing with. I'll update once it's all sorted!