545 RPM problem
#11
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Do these things have PCV valves? Hard to start when hot sounds sort of sounds like a classic PCV valve issue. Search around, they are cheap and generally easy to change. You may even be able to test it by shaking it. You should hear a ball bearing shake around. If it is all oily and you can't hear the ball bearing shake, it probably needs replaced.
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#12
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My Ride: 2004 545i Sport Pak
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If you're referring to Mass Air Flow sensor then beyond my expertise, but I would imagine it could cause all sorts of problems including hard to start, rough idle, reduced performance, reduced gas milage. But I would think you would get a warning if your MAF is having trouble.
#13
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My Ride: Alpine White 2006 530Xi (SLD)
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Why not try to clean the MAF sensor? That's where I'd start. If problem's still there after a good cleaning, start looking at coils, engine management and so forth. But start with the easiest cheapest fixes and work your way up. Worst case, you'll end up with a mini tune up. Speaking of tune ups, how many miles on your car and when was the last time you took it in for one?
Good Luck
Good Luck
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#14
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My Ride: 2004 545i Sport Pak
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No our 5ers do not have Positive Crankcase Valves however, we (545,550) do have Pressure Regulating Valve instead. They serve pretty much the same purpose, and mine at the time illuminated the CEL.
Check this DIY I did last year with detailed pics on page 4:
https://5series.net/forums/topic/853...e/page__st__45![](https://5series.net/forums/public/style_emoticons/default/thumbsup.gif)
Check this DIY I did last year with detailed pics on page 4:
https://5series.net/forums/topic/853...e/page__st__45
![](https://5series.net/forums/public/style_emoticons/default/thumbsup.gif)
#15
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