BMW 1 Series Timing Chain Rattle Signals Major Issue

I had very similar issues with my 2018 BMW 2 Series diesel. Initially, I also thought it was timing chain related due to the metallic noise, but it turned out to be a faulty crankshaft sensor. Had it checked at the garage last month, the sensor was sending incorrect signals to the ECU, causing poor fuel economy and reduced power. The metallic noise was actually unrelated and came from a slightly loose timing chain tensioner. They replaced the crankshaft sensor and adjusted the tensioner. The whole job took about 4 hours. Not a super serious issue if caught early, but it could have led to bigger problems if left unchecked. The symptoms match yours exactly, engine light, power loss, high fuel consumption. I'd definitely get it checked soon, as running the engine with incorrect sensor readings isn't good for long-term reliability. Worth noting that these sensors can fail without warning on our generation of BMW diesels. It's actually quite common after 50-60k km.

Hey, thanks for sharing that info! I had the exact same problem with my 1 Series. Those symptoms are spot on with what I experienced. Really helpful to know about the crankshaft sensor, that's exactly what it was in my case too. Just wondering, do you remember roughly how much you ended up paying for the fix? And has everything been running smoothly since the repair? I'm curious because sometimes these issues can pop up again.

Hey there! Happy to update you on how things turned out with my 2 Series. Yeah, the repair was definitely worth it, ended up paying 340 € for the crankshaft sensor replacement. Since getting it fixed, my car's been running like a dream. The Crankshaft to camshaft reference value is now perfectly normal, which was the root of our shared problem. The fuel economy is back to what it should be, and that annoying power loss issue is completely gone. Haven't had a single warning light since then, and it's been about two months now. The engine's running super smooth, especially during those cold morning starts that used to worry me. The mechanic mentioned these sensors typically last quite a while once replaced, so I'm not too concerned about it happening again. Just keep an eye on your engine performance, if you notice anything odd, best to get it checked right away rather than waiting. Hope your 1 Series is treating you well after the fix too!

Thanks for the update! That's really reassuring to hear. After taking my car to the mechanic yesterday, I'm super relieved it's all sorted now. The repair bill came to just under 400 € for me, a bit more than yours but included some diagnostic work. The mechanic was actually really thorough and showed me the old sensor, it was completely shot. They got it done in about 3 hours, and I could tell the difference as soon as I started the car. The fuel consumption has improved dramatically, and that annoying metallic noise is completely gone. It's like driving a different car now! The engine's got all its power back, and it's running so much smoother. Funny how we both had such similar experiences. Really appreciate you sharing your story, it helped me understand what I was dealing with. I'll definitely keep an eye on things, but it's good to know these fixes tend to last. Best decision I made was getting it sorted quickly rather than waiting for it to get worse.