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

by in Columbia, SC on February 01, 2011
1 answer 3 comments
ANSWER by , February 01, 2011
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. Zee
COMMENT by , February 02, 2011
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
COMMENT by , February 02, 2011
Yes, they are correct. Make sure they will replace the hoses also. Zee
COMMENT by , February 02, 2011
zee, you certainly are a reliable source.....ie 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.