Hi,

Does anyone had problem with RPM`s on hot engine? When I stay on traffic lights my RPM`s gone crazy, they swimming from 600 to 900. It could be Mass Air Flow Sensor?

 

Does the CEL (check engine light) illuminate? Any idrive warnings? Check the pressure regulating valve or it could be as simple as a hose coming loose - a vacuum leak somewhere posibly. Good luck

 

CEL doesnt illuminate, no infos on idrive. Just when driving up to 2k RPM engine swims over 2 k everyting is ok. When idle also swimming RPMs. I tried To disconnect MAF and engine doesnt want to start. What is Pressure regulatinbg Valve? PCV?

 

make sure to try the easy stuff first, my RPM's drifted at lights too, when I changed the air filter it smoothed right out.

 

Similar problem for me and my 545. Asked the dealer to fix on my last two visits but no change.
Would be interested in a solution to this niggle.... anyone?

 

Ignition coil?

 

I have also problems with engine start when is hot (operating temerature). It looks like he start wihout some cylinders ant keep starting unless all cyl starts. Normally it starts fast but last time it needs 3-4 sec more.

 

I have also problems with engine start when is hot (operating temerature). It looks like he start wihout some cylinders ant keep starting unless all cyl starts. Normally it starts fast but last time it needs 3-4 sec more.

it looks this same like mine, what is this?

 

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.

 

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