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94 5.7 What is best way to Find if have Broken Valve Spring

Discussion in 'The Garage' started by stano, Nov 25, 2005.

  1. stano

    stano 1/2 ton status

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    1994 5.7 C1500 What is the best way to find out if you have a broken Valve Spring. We have not yet taken a comp test to see if one cylinder is acting diferent or diferent value. We will do this tomarrow.

    The valve cover is off as of just before dark. and we pushed on the rocker with a large screw driver, straight on, to feel a weak one but they all felt the same. Really need to do the push on rocker test again because I was in a hurry before dark. We will look tomarrow with a mirrior stick.

    But what about under the skirt of the top of the spring.

    Is there a on engine tester..

    thank you
    stano
    87 K5
     
  2. Leper

    Leper 1/2 ton status

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    IMO a leak down tester is better than a compression tester.
     
  3. diesel4me

    diesel4me 1 ton status Premium Member

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    one way...

    I'd use a vacuum gauge..a broken spring should show right up on a vacuum gauge at idle--if not at idle,then at higher RPM's... you wont even have to get dirty...

    Usually if they break,you'll find a peice of the broken coil of the spring floating around on the head somewhere..and you can usually see them too..holding your hand on the rockers with it running after a cold start (so your hand wont get burned!) its readily apparent if one spring is broken,you can "feel" the difference in the way the valve closes compared to the others..

    When all else fails,taking the springs OFF is about the only sure fire "test"..I've found a few broken ones on motors that ran perfectly,that I was just going to install new valve stem seals on! :eek1: ..weak springs can LOOK good,but make a motor run like ca-ca too..have them tested,or replace them all,especially if you have a higher lift cam than stock.. :crazy:
     
  4. stano

    stano 1/2 ton status

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    At idle (warm) we are getting the vaccum gauge at manifold vaccum to shake about two needles wide barely. at 18 to 19 psi (hg)....

    The needle is very steady all other places.

    Except driving and in overdrive about 1400 Rpm (42 43 mph) and accelerating without letting shift out of overdrive, the vaccum gauge will shake again a little more than idle warm, (two needles or more slower shake).

    Thought we would check for broken valve spring (advised from Chevy talk).

    thank you
    stano
    87 K5
     

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