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Heater output on my 87 K5

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BlackK5, Mar 21, 2002.

  1. BlackK5

    BlackK5 Registered Member

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    I have an 87 K5. 350 c.u. I have never been impressed with the heater output. Just doesnt seem to warm up the cab very well. Do the heaters in these things just suck, or is my heater core's number up!
     
  2. radar

    radar Registered Member

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    I have a 86 K5 and my heat kicks ass!!!
    When is the last time you flushed out your heating system?
    Also what tempeture thermostat do you have?
     
  3. Kyle89K5

    Kyle89K5 1/2 ton status

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    Before you shell out cash to get a new heater core, flush it. It will only take about 10 min.'s and should help out a ton. Flush and backflush the core till you get clear water. Saved me some cash on my 89. Made a HUGE defference too.
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    AC or not, HD heating option or not? There IS a difference. Stock Non AC heaters suck.
     
  5. CaptCrunch

    CaptCrunch 1/2 ton status

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    try backflushing like others have said... otherwise check the engine temp/thermostat. If that fails it is most likely the core and they aren't the easiest to replace.
     
  6. BlackK5

    BlackK5 Registered Member

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    Flushed just this past fall. I have a 210 degrees thermostat in it ( I am assuming...since that is what the temp gauge reads when engine is warmed up).
     
  7. possum

    possum Registered Member

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    maybe sound like a silly question... but how do you flush out the heating system?
     
  8. possum

    possum Registered Member

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    may sound like a silly question... but how do you flush out the heating system?
     
  9. TopOff

    TopOff 1/2 ton status

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    Check all your heating vents for proper operation.

    Also check your heater hose vacuum actuater valve is working properly. This is supposed to close when you turn on the A/C.

    Good luck
     

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