BMW 5 Series Idle Trouble: Fuel Pressure Regulator Fix?

Just went through something very similar with my 2007 BMW 3 Series diesel. After changing the fuel filter, I had the same symptoms, rough idle, power loss, and engine warning light. Turned out the fuel pressure regulator wasn't the culprit. The real issue was air trapped in the fuel lines after the filter change. Had to take it to my mechanic, who performed a proper fuel system bleeding procedure. The system needed professional bleeding equipment to get all the air pockets out. They also cleaned the fuel pressure sensor while they were at it, as it was giving false readings due to some contamination. It wasn't a major repair job, but definitely needed professional attention. The symptoms cleared up completely after the proper bleeding and sensor cleaning. The car's been running smooth since then. My advice: Get it checked by a BMW specialist who has the right diagnostic equipment. These symptoms often get misdiagnosed as regulator issues when it's actually something simpler.

Thanks for sharing your experience! Glad to hear you got it sorted out. You've given me hope it might not be as serious as I feared. I'll definitely look into getting the fuel system bled properly. Quick question, do you remember roughly how much you paid for the repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up?

Hey there! Glad I could help earlier. Yeah, everything's been running perfectly since I got it fixed. The total bill came to 45 € for diagnosing and fixing the error after the fuel filter change. It turned out I was right about the fuel pressure regulator being defective, that was actually the root cause, not just trapped air like I initially thought. The mechanic replaced it, and it made a world of difference. My BMW's been running like a dream since the repair, no more rough idling, stalling, or power issues. The engine warning light hasn't come back on either. Sometimes these things sound scarier than they actually are, you know? If you're still having trouble, I'd definitely recommend getting it checked by a proper BMW specialist. Having the right diagnostic equipment makes all the difference when trying to pinpoint these kinds of issues. Honestly, considering how much better the car runs now, it was money well spent. These older BMWs are great cars when they're properly maintained, despite the occasional problem.

What a relief! Thanks for all the details, that's actually a pretty reasonable price for the fix. I finally took your advice and went to a specialist mechanic yesterday. You were spot on about needing proper diagnostic equipment. Turns out my issue was actually pretty similar to yours. The mechanic found a faulty fuel pressure regulator and some trapped air in the system. Got it all sorted in about an hour. The whole thing cost me a bit more than yours, but the car's running like new now. No more stuttering or power loss, and that annoying check engine light is finally off! Can't believe I spent so much time worrying about this. Should've just gone to a proper specialist from the start instead of trying unusual mechanics. Really appreciate you sharing your experience, it definitely pointed me in the right direction. Think I've found my new go-to mechanic too!