pcv valve replacement. on 2000 BMW 528i

mechanic told me that i need to replace the pcv valve.... i dont know how he came to this, but auto is running rough.
auto has 215m miles ... sometimes feel a miss, and sometimes a lunge(at stop light)... otherwise still going ok... must keep driving, but mech insist that performance would improve with this pcv thing.... approx est cost 550.00...... i cannot find pcv replacement on your website. thanks donwalters

Asked by for the 2000 BMW 528i
Bad PCV could cause these symptoms, since unmeasured air enters into the intake.
PCV (Crankcase Vent Valve) could be tested by a manometer.
It's from the BMW repair manual:
A properly functioning pressure control valve is designed to maintain a slight vacuum (approximately 10 - 15 mbar ) in the crankcase which assures reliable crankcase venting during all engine operating conditions.

A malfunctioning crankcase ventilation valve may cause the following complaints:

* Engine runs rough
* Whistling noise from crankcase ventilation valve
* Check engine light on - possible DME faults stored: misfire all cylinders, oxygen sensor/mixture faults, etc.

You can do this:
While the motor is running at normal operating temperatures, loosen up the oil filler cap and try to lift it up. If there is a strong vacuum sucking the cap back, the PCV valve is bad.

I don't know if their estimate includes all the vent hoses, I'd strongly suggest to replace those also.

thanks Zee, this makes sense.... apparently this replacement involves getting to the problem....service center said it was a 4 hour job.. i guess that why is so expensive.... thanks again. donwalters
Yes, they are correct. Make sure they will replace the hoses also.

zee, you certainly are a reliable
read your suggestion
went home for lunch.
parked in drive, engine on, remove oil cap
and whatda you know....
it had a 'magnet feel' to the cap held above the oil thing hole.
or at least like a gravity pull.

thanks to you, my mechanics suggestions are confirmed.

thanks to you and repair pal...donwalters

ps im trying to nurse 300000+ miles outta this ole ride...hopefully this pcv valve thing works toward that end.