[535_BiTurbo]

Testing my vaccum; On a turbocharged car, when we remove the oil filler cap, is there supposed to be a slight suction which confirms the CCV is functioning properly. I know Naturally Aspirated engines have a slight suction, but I wasn't sure about turbocharged engines.

The reason I ask is because I removed my oil filler cap and placed a rubber glove over the oil filler opening and the glove filled up a little. So Im wondering if my CCV/PCV valves needs to be replaced on my F10 550i???

[badblack550xi]

Originally Posted by 535_BiTurbo

Testing my vaccum; On a turbocharged car, when we remove the oil filler cap, is there supposed to be a slight suction which confirms the CCV is functioning properly. I know Naturally Aspirated engines have a slight suction, but I wasn't sure about turbocharged engines.

The reason I ask is because I removed my oil filler cap and placed a rubber glove over the oil filler opening and the glove filled up a little. So Im wondering if my CCV/PCV valves needs to be replaced on my F10 550i???

how many miles

[535_BiTurbo]

Originally Posted by badblack550xi

how many miles

133k miles, no rough idle, no codes, etc.

[Willisodhiambo]

They don't seem to have appreciable vacuum like the NA engines. Mine has almost none at all. If your oil consumption is OK and no leaks through your seals then I would guess there us nothing to worry about.


As per ISTA.......
Ambient pressure is 0.95bar, very slight vacuum
0.8 bar, pressure control valve faulty
1.07 bar, clogged system or kinked vent line

Atmospheric pressure is 1.01bars, so I am interpreting this to mean that if you have +pressure then system is clogged! Not sure what the solution is for positive pressure rather than excessive negative pressure.