Luke Warm Heat

Discussion in 'Engine Performance + Maintenance' started by oldbrown, Jan 5, 2019.

  1. oldbrown

    oldbrown Newbie

    Messages:
    11
    Likes Received:
    6
    Joined:
    May 13, 2018
    Location:
    Crown Point Indiana
    Have a 91 K1500. Truck gets up to temperature but heat is only about 105 out of the vents. I flushed the heater core and put in a new thermostat with no real changes. Only other thing I can think of is the coolant is not circulating well. No noises or leaks from water pump. Any ideas? Thanks.
     
  2. smdk2500

    smdk2500 I'm Awesome

    Messages:
    181
    Likes Received:
    24
    Joined:
    Dec 26, 2017
    Location:
    Armpit of the universe Nebraska
    Are the hoses on the inlet and outlet of the heater core the same temp or is one significantly cooler then the other one?
     
  3. studigggs

    studigggs Newbie

    Messages:
    39
    Likes Received:
    13
    Joined:
    Feb 19, 2018
    Location:
    CA
    Blend door actuator could be toast or the flap that allows the air to move through the heater core could be jammed.
     
    kennythewelder likes this.
  4. Brandon Schnautz

    Brandon Schnautz Supporting Member

    Messages:
    30
    Likes Received:
    4
    Joined:
    Sep 4, 2018
    Location:
    Houston, Texas
    I'm going with this guy ^
     
    kennythewelder likes this.
  5. Kv5137kv5137

    Kv5137kv5137 OBS Enthusiast

    Messages:
    86
    Likes Received:
    6
    Joined:
    Jul 19, 2018
    Location:
    New york
    CHeck the heater hoses. If they get hot. Check the upper radiator hose. Both should get hot. Open the havoc. Heck the blend door operation. Two or three depends. Fan? Check the way the heater core is positioned it should be insulated with that brittle factory foam if not but some and seal it. That is what was wrong with mine


    Sent from my iPhone using Tapatalk
     
  6. bamabound

    bamabound Newbie

    Messages:
    4
    Likes Received:
    0
    Joined:
    Nov 24, 2018
    Location:
    dadeville, al
    either bad heater core or blend door actuator. i'd guess heater core is plugged up. my brother just had the same symptoms & it was the heater core. he said it was pretty easy to replace.
     
  7. xx94Z71xx

    xx94Z71xx Newbie

    Messages:
    32
    Likes Received:
    4
    Joined:
    Dec 9, 2018
    Location:
    Niagara Falls
    when you flushed your heater core did u back flush it? in the out and out the in? thats what i had to do to unplug mine. i kept alternating which side i put the hose on. i did that a couple times and it was clear water then bam it was sludge city. My heat was like 10x hotter afterwards but i spent a good hour or two doing that.
     
  8. oldbrown

    oldbrown Newbie

    Messages:
    11
    Likes Received:
    6
    Joined:
    May 13, 2018
    Location:
    Crown Point Indiana
    Thanks guys
    I plan to look at the blend door
     

Share This Page