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pcv valve sounds like a bug zapper!

Discussion in 'GM Powertrain' started by silleffej, Dec 22, 2010.

  1. silleffej

    silleffej Member

    I just went out and checked my 1990 5.7L 350 for shorts in the wiring since a mechanic told me at night is the best time to do so. I noticed my pcv valve sounded like a bug zapper buzzing. I am pretty sure this is not normal but I just replaced my pcv valve back in October. I have been doing a lot of diagnostic work on my vacuum lines and egr. Does the buzzing mean it needs replacing already???
  2. stephan

    stephan Rockstar 4 Years 5000 Posts

    Usually they start buzzing when they are worn out & there is too much clearance btw the ball & the housing, but since you just replaced it in October I'm thinking maybe it's just an inferior brand (China/Taiwan/Mexico) & not made to proper tolerance.
  3. silleffej

    silleffej Member

    btw ball and housing,

    are you talking about the rubber grommet the pcv plugs into?
  4. stephan

    stephan Rockstar 4 Years 5000 Posts

    NO, not the rubber grommet. The ball is inside the PCV housing. That is what is rattleing back & forth & buzzing.
    Where did you buy it? Pop it out & see if you can read the vendor on it somewhere.
  5. silleffej

    silleffej Member

    it was bought at local auto parts store, I think it is china made. It was rather cheap. would a higher end pcv really perform better?

    ---------- Post added at 10:21 PM ---------- Previous post was at 10:18 PM ----------

    I don't even know if there is a such thing as a higher end pcv valve. I have never seen one cost more then a couple of dollars.
  6. stephan

    stephan Rockstar 4 Years 5000 Posts

    Yes there is a difference btw a good one & a bad one. Yours is a bad one. I've had mine in my truck for 35,000 miles & it's still good. I know you haven't put many miles on your burb since October, so the pcv you got is just a cheap one.
  7. silleffej

    silleffej Member

    I took the pcv valve out and shook it. I can still hear a rattle, doesn't that mean it is still good? I will probably replace it anyway but just checking.
  8. stephan

    stephan Rockstar 4 Years 5000 Posts

    Yes & no. They should rattle when you shake them up & down. This tells you that it is not stuck with crud inside & doesn't need cleaning. That is a test on an old one to see if it is still free, & NOT STUCK, but this is not the problem with yours. Yours is TOO FREE.. You just need a better quality one.

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