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  1. #1

    Default good a/c-lukewarm heat

    have a 1995 silverado with 5.7 engine-the a/c is good.but the heat comes out lukewarm.check hoses and all are warm.temp guage goes up to midway range and the suddenly drops to 160.stays there most of the time,but does raise occasionly to 180,have a 195 thermostat and the anti-freeze is good,anyone have any ideas what the problem could be.post or email pbates3004@live.com

  2. #2

    Default

    did u ever replace the thermostat ?? i would say its shot ?? also check for air in the system....mmmhhhh just guessing....

    1996 Suburban K3500 SLT DUALLY
    1988 Camaro RS 383 stroker LT1
    1992 32' Aero-tek Race Boat, 600 CI BBC
    WE CAN STICK A DIESEL IN ANYTHING
    SPECIALIZED IN CUSTOM CONVERSIONS OF ANY KIND
    Scott:glasses:

  3. #3

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    Quote Originally Posted by earnhardt724 View Post
    have a 1995 silverado with 5.7 engine-the a/c is good.but the heat comes out lukewarm.check hoses and all are warm.temp guage goes up to midway range and the suddenly drops to 160.stays there most of the time,but does raise occasionly to 180,have a 195 thermostat and the anti-freeze is good,anyone have any ideas what the problem could be.post or email pbates3004@live.com
    The Heater Core is most likely Clogged.....so only a small amount of Coolant is flowing through it......Went was the last time the Coolant was Flushed??


    MIKE


    99"SILVERADO
    5.3 l 3.73 l G80
    BLACK BEAR CUSTOM TUNE
    SNUGTOP l COLORMATCH l KATZKIN










  4. #4
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    Default

    Hey Earnhardt, welcome to the GM truck club..
    I agree with both thermostat & heater core ideas above, but the thermostat is the most likely suspect here, because you say your temp guage is fluctuating.. It should not do this. It should rise to 195 degrees F & stay there. Remember, thermostats are to set the minimum temperature of your engine, & they have nothing to do with maximum temperature unless it is stuck closed. It is much cheaper & easier to replace the thermostat than the heater core, so replace it first.


    It is 95% probability that the thermostat is the problem in your case because your engine temp should not go back down to 160 unless the thermostat is opening back up too far & letting too much coolant to pass from the radiator into your engine.
    Last edited by stephan; 11-25-2010 at 02:25 PM.
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
    Holley 650, Flowtech Headers, Magnaflow exh.
    Jet Trans 700R4, B&M Ratchet, 4:10 gears,
    3" susp. lift kit "shadetree"
    No rev limiter, No speed limiter lol


  5. #5

    Default thanks

    thanks to all for inout,it was the thermostat,all is good now.

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