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heater question

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by kmcnish320, Dec 17, 2011.

  1. kmcnish320

    kmcnish320 New Member

    quick back story. i have a 88 suburban it was having heater problems and i read on another thread that it might be the heater core. when i went in to change it out i noticed that the lever that controls the temp i guess was not sitting properly so i went in and moved it back to where it was looked like it was supposed to be. i let the truck run for 30 mins with the heater on and i noticed that the air got worm in my frustration from dealing with other things on the truck i stomped my foot and hit the gas pedal by accident when i did that the heater started blowing hot air. now my question, is that how its supposed to be or should i just go ahead and put the new heater core in there?
  2. dipstick

    dipstick Member 2 Years 100 Posts

    Would not think heater core. when you hit the gas more fluid flowing through heater core .
    Might be low coolant.. thermostat stuck .half way open.. impellers on water pump shot.
    Check thermostat first and coolant.
  3. TMair

    TMair Member

    +1

    Biggest problem with heater cores is when they decide to leak, low coolant level will cause you to loose heat, but so will the valve that allows more coolant to flow through the heater core, I would look there first as suggest by dipstick!
    Terry
  4. kmcnish320

    kmcnish320 New Member

    i replaced the thermostat and topped of the coolant. ran the it for about 20 mins. still staying warm but its not getting hotter as i rev the engine as for the water pump that was replaced last week. think i might have a bad on in there? and no the engine does not over heat. so i am at a lost at what else to do. by the way thanks for all the help i am getting
  5. dipstick

    dipstick Member 2 Years 100 Posts

    Did you put a 195 tstat. Only thing i can think of heat exchanger not working right ..thing cable hooked to
  6. kmcnish320

    kmcnish320 New Member

    yes the box says 195 i hope that is correct. a quick update, when i lowered the fan speed it got nice and toasty so maybe that's the problem? don't put the heat on full blast like its a new car?
  7. coversguy

    coversguy New Member

    Its also possible to get an air lock in the system when you re-fill a drained system, causing a reduced amount of coolant to flow through the heater core, especially when the engine is idling. As you rev the engine it causes more coolant to flow through the heater core, and you can feel the difference in terms of warmer air. If you think this might be your problem you can try revving the engine up and down, up and down, and so on several times. Then check the coolant level and see if it will take more. Good luck.
  8. TMair

    TMair Member

    I think I would also check the regulator that allows water to flow through the heater core, when you turn you temp control down it just changes how much water volume can flow through the core, if this is not moving it's full rainge, or at all it could be your problem.
    Terry
  9. kmcnish320

    kmcnish320 New Member

    I've gotten all the air out of the system finally there is no leaks. air still not getting very hot. its warm but i know it should be warmer than that. i did run into another problem yesterday. after running the heater almost all day when i finally called it a day i turned the truck off. funny thing the blower stayed on. i ended up have to disconnect the battery to get it to turn off and in the process fond the positive terminal was stripped out. but i was able to check and made sure the blower didn't turn back on after power was supplied. any ideas on what could cause that? or do i have gremlins in there and they just moved on to a different part of the truck?
  10. JZ_745

    JZ_745 New Member

    Did you get this figured out??? I'm having the same issues (temperature...not fan) with my 99 burb. My next option is to flush the system and replace the coolant. I'm concerned the previous owner put stop leak in the radiator causing some plugging. Let me know!!

    JZ

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