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jlhram
01-17-2009, 06:50 PM
What would cause a pcv valve to start vibrating like crazy, I replaced it with a new one and it's worse, sounds like a swarm of bees under the engine, and the car started idling like a washing machine. Thanks...Jim

wilks3
01-17-2009, 07:24 PM
Check intake bolts for torque. Sounds like vacuum is pulsing.

cudabob496
01-18-2009, 02:18 AM
Sounds like it is not the PCV valve. Do you have a breather on one of your valve covers. Did you change anything recently on the engine, or do any kind of work?

jlhram
01-25-2009, 05:13 PM
I did a cam swap. I've got the pcv on pass. side and a filter on the drivers side. Checked intake all good even used some sarter fluid and sprayed around no change. I did try something today moved the pcv line from the front to the back of the carb, some improvement but not much.

wilks3
01-25-2009, 05:18 PM
Have you put a vacuum gauge on? Steady or shaky? This all started after cam change?
Maybe pushrod holding holding a valve open alittle.

wilks3
01-25-2009, 05:22 PM
Pull PCV out of valve cover with motor running, hold a piece paper on the end of PCV, should suck in, if it pulses you have something not closing all the way.

crisser
01-25-2009, 05:46 PM
I had an Oldsmobile 350 do this to me before. Changed to a new Autozone type valve, same problem. Changed to an AC Delco valve, problem solved.
So, maybe put a high quality valve?

turbododge
01-25-2009, 08:56 PM
You most likely have the wrong pcv valve for the vacuum that the cam is giving you. Probably not enough vacuum to hold it off the seat, plus the pulsing of a high overlap cam. You will need to find something with less spring rate in it that is setup for low vacuum situations.

jlhram
01-26-2009, 08:41 AM
Thanks, any suggestions on what pcv to try?

turbododge
01-26-2009, 11:40 AM
I haven't had to look for a low vacuum one for a long time, as the turbo cars I have had for last 20+ years have good vacuum. Way back, we used to be able to get them at the local (long gone) high performance shop. You may be able to find something on a Googel search.

If not, maybe someone here knows what stock vehicles had the lowest vacuum from the factory.

passing you
01-26-2009, 09:01 PM
I wonder if the valve/s are seating.

pishta
01-26-2009, 11:02 PM
I haven't had to look for a low vacuum one for a long time, as the turbo cars I have had for last 20+ years have good vacuum. Way back, we used to be able to get them at the local (long gone) high performance shop. You may be able to find something on a Googel search.

If not, maybe someone here knows what stock vehicles had the lowest vacuum from the factory.

Ford Boss 302, that car would almost stall if the dome light came on...

pishta
01-26-2009, 11:06 PM
Almost sounds like you lost some ring control. Try shootin a squirt of oil in each cylinder and starting up to see if the flutter is evident in the first few smokey seconds.

turbododge
01-26-2009, 11:18 PM
How much vacuum do you have at idle? If you pull the pcv out from the valve cover with the engine idling, the piston should be bottomed out toward the carb. You can put a small screwdriver or rod in the end to confirm you can't move it further than the vacuum is pulling it. If it is not seated, or is bouncing, you either need more vacuum or less spring.