BMW E39 530d Power Loss: CCV System Under Suspicion

Hey there! I had a similar issue with my 2003 BMW 525d (also had a chance to work on the 528i). I've got some experience working on cars, mainly basic maintenance and troubleshooting. What you're describing sounds exactly like what I dealt with, engine light, power loss, and unstable speed. Mine turned out to be a faulty crankcase ventilation system. The symptoms match perfectly. Had it fixed at my local workshop last year, cost me around 360 for parts and labor. They had to replace the entire CCV unit and some connecting hoses that had deteriorated. Before jumping to conclusions though, could you share: Any unusual sounds from the engine? Does it smoke more than usual? When did these symptoms first appear? This info would help confirm if you're dealing with the same issue I had.

Thanks for sharing your experience! Mine's at 155982 KM and had its last service about 3 months ago. To answer your questions: I've noticed a slight whistling noise under the hood, especially when accelerating. No unusual smoke, though. The symptoms started gradually over the last couple of weeks, but got really noticeable during highway driving last weekend. I was actually hoping it would be the CCV since it seems like a common issue and not too expensive to fix. Good to hear about your repair costs, gives me a rough idea of what to expect. Did you notice any immediate improvement after the repair?

Hey again! Ah yes, that whistling sound, that's exactly what I heard too! When you mentioned the highway driving issues, it really clicked because that's where I first noticed my problems getting serious too. After my CCV replacement, the difference was like night and day. The whistling disappeared completely, and the power came back instantly. The engine felt much smoother, especially during acceleration. It's been about a year now since the fix, and I haven't had any related issues since. Your mileage is actually pretty close to what mine was when I had the problem (mine was around 163000 KM). The gradual onset of symptoms is also typical of CCV failure, it doesn't usually happen overnight. One thing I'd suggest, while they're in there replacing the CCV, have them check the connecting hoses too. In my case, some of them were pretty brittle and needed replacement. Might save you another trip to the shop down the line. Let me know how it goes after you get it fixed. These BMWs are great cars when everything's working right! James

Thanks so much for all that detailed feedback! It's really helpful to hear from someone who's been through the exact same thing. Your experience matches my symptoms perfectly, especially that whistling sound you mentioned. Really reassuring to know it's likely just the CCV and not something more serious! That's a great tip about checking the hoses while they're at it. I'll definitely mention that to my mechanic. I've already booked the car in for next week, and honestly, I can't wait to get this sorted. The highway driving has been particularly stressful lately. I'll make sure to update you on how everything goes after the repair. Keeping my fingers crossed for that same "night and day" difference you experienced! Thanks again for taking the time to share all this info, it's been super helpful in understanding what I'm dealing with. Will let you know how it turns out!