BMW VANOS Symptoms Point to Costly Engine Repairs

Hey there! I had nearly identical issues with my 2017 BMW 4 Series last summer. The symptoms you're describing match what I experienced, rough idle, poor fuel economy, and that annoying check engine light. My diagnosis turned out to be a faulty camshaft solenoid valve in the VANOS system. The mechanic also found some wiring issues affecting the power supply to the VANOS unit. It was definitely a serious problem that needed immediate attention since it was affecting engine timing and performance. Got it fixed at an independent BMW specialist. They had to replace the solenoid valve and repair the wiring harness. It wasn't a quick fix, took them about two days to complete all the work, but the car has been running perfectly since then. The engine response is back to normal, and fuel consumption returned to standard levels. Given your mileage, this sounds very similar to what I faced. I'd strongly recommend getting it checked by a specialist who knows VANOS systems well. These issues typically don't resolve themselves and can lead to bigger problems if left unaddressed.

Hey, thanks for sharing your experience! Sounds exactly like what I'm going through with my car. Quick question, would you mind telling me roughly how much you ended up paying for the whole repair? Also, has everything stayed running smoothly since then, or have you noticed any other problems? Just trying to get an idea of what I might be looking at here with my own repair.

Hey again! Absolutely happy to share the details, just had this fixed a few months ago and it cost me 250 € in total. The mechanic sorted out the Inlet VANOS issue, which turned out to be exactly what I suspected, a defective camshaft solenoid valve. I'm actually really pleased with how everything's running now. The car feels like new again, no more sluggish performance or rough idling. Fuel consumption is back to normal too, which is a huge relief for my wallet! Haven't had a single problem since the repair, and the check engine light has stayed off. If yours has the same symptoms, I'd definitely recommend getting it checked sooner rather than later. The repair wasn't as expensive as I initially feared, and it's totally worth it for how much better the car runs now. My mechanic mentioned that catching these VANOS issues early can prevent more expensive problems down the road. Just make sure you find someone who really knows their way around BMW VANOS systems, it makes all the difference in getting it fixed right the first time.

Thanks for all that info! I actually just got back from a mechanic who specializes in BMWs. You were spot on, it was the camshaft solenoid valve causing all the trouble. Cost me a bit more than yours at 350, but they also found and fixed some worn-out wiring while they were at it. What a difference! My car's running like a dream now. The engine's smooth, that annoying rough idle is gone, and I'm already noticing better fuel economy. No more check engine light either. The mechanic was really thorough and walked me through everything they did. They even showed me the old parts and explained what went wrong. Really glad I didn't put this repair off any longer. The whole experience wasn't nearly as painful as I'd feared, both for my car and my wallet! Thanks again for pointing me in the right direction with your experience. It really helped me know what to expect and what questions to ask.