Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

heating up the heater?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BranndonC, Jun 3, 2002.

  1. BranndonC

    BranndonC 3/4 ton status

    Joined:
    Mar 18, 2002
    Posts:
    8,591
    Likes Received:
    0
    Location:
    Anaheim, Ca
    How would i go about increasing the temp of the air coming from the heater? mine is warm now, but not really enough to heat you up on freezing cold nights. Any suggestions? also i kinda smell a sweet wierd smell sometimes, does that mean my heater core is bad? and how difficult is it to replace?
     
  2. Tweetysuarus

    Tweetysuarus 1/2 ton status

    Joined:
    May 25, 2002
    Posts:
    2,294
    Likes Received:
    0
    Location:
    Lynnhood,WA
    That sweet smell is anti freeze leaking and you might wanna change the thermostat to a hotter one for the winter months.
     
  3. BranndonC

    BranndonC 3/4 ton status

    Joined:
    Mar 18, 2002
    Posts:
    8,591
    Likes Received:
    0
    Location:
    Anaheim, Ca
    i never see antifreez where i park... is it possible to just leak while driving? is the thermostat just something i can pick up at pepboys and install my self fairly easily? changing the tranny oil is about the extent of my mechanical skills.
     
  4. Tweetysuarus

    Tweetysuarus 1/2 ton status

    Joined:
    May 25, 2002
    Posts:
    2,294
    Likes Received:
    0
    Location:
    Lynnhood,WA
    Yes pepboys has the thermostat & yes you can change it yourself as for the leak look on the floor around the heater box on the passenger side or in the heater box or check the heater hoses that go to the firewall and Radiator check your whole cooling system out but find that leak. Espeacially if there are aniamls around cause anti-freeze in poisonous to them.
     
  5. Can Can

    Can Can Pusher Man Staff Member Super Moderator

    Joined:
    Feb 17, 2000
    Posts:
    15,552
    Likes Received:
    136
    Location:
    Cochrane, Alberta, Canada
    Man, if you don't mind crawling under your truck and getting splashed by ATF, then doing the thermostat is going to be a breeze.

    Just drain your rad, undo the thermostat housing, and pull the old thermostat out. Now make sure that you clean the faces really well(scrape off all the old gasket material) and reinstall the new gasket and thermostat. Refill your rad and check for leaks.

    It's that simple. Don't be afraid to spend the extra couple of bucks on an upgraded thermostat.
     
  6. Mingler

    Mingler Registered Member

    Joined:
    Nov 2, 2001
    Posts:
    29
    Likes Received:
    0
    Location:
    Calgary, Alberta
    That sweet smell can only be one thing. Coolant.
    Double check your whole cooling system (follow the hoses) and if you don't find any leaks....there's a possibility you have a pin-hole leak in your heater core. (Not uncommon).

    As for the warm air issue. You could have air in your heater core from that possible hole. In some instances, your system will not circulate the full amount of coolant through the core because of this causing cooler air. Could also be due to your thermostat being stuck open. (Even a low temp thermostat should produce hot air.)

    Try poping off the rad cap (with a cold engine of course) run the engine till it's hot, have someone rev the engine at about 1200 RPM to get the coolant circulating. This can sometimes "Burp" the system to clear the air bubbles. If you notice your coolant level "really" drop during reving you may have got the culprit. Add more coolant while continueing to rev the engine.
    IMPORTANT - make sure you get the rad cap on before your buddy stops reving.......makes a real mess otherwise.!!!

    Onec you do that, You may notice that sweet smell a little more.....if this is the case....you found your leak as well....Heater Core!

    Hope that helps you out some.
     
  7. BranndonC

    BranndonC 3/4 ton status

    Joined:
    Mar 18, 2002
    Posts:
    8,591
    Likes Received:
    0
    Location:
    Anaheim, Ca
    ok, i'll change it out. two quick questions...
    1. is there a visible way to tell if it's bad?
    2. on the passenger side inside the truck near the kick panel on the floor, there's a oval shaped piece of plastic vent of some sort... what is that and how important is it that that is working properly?
     
  8. m j

    m j 1/2 ton status

    Joined:
    Dec 28, 2001
    Posts:
    4,606
    Likes Received:
    0
    corrosion causes the heater core to leak,
    I guess it could also block the coolant flow.

    I always drill a small hole (1/8 or so) in the thermostat to ease the removal of air from the system
     
  9. creampuff90k5

    creampuff90k5 1/2 ton status

    Joined:
    Feb 15, 2002
    Posts:
    142
    Likes Received:
    0
    Location:
    New Jersey
    Others have given you the right advice about getting a higher temp thermostat. When I was living in FL, I ran a 160 degree unit as recommended by my computer chip manufacturer. Right before moving to the Northeast, I switched to a 180 degree therm, but even that wasn't enough for really terrific heat. Finally, I tried 192 degrees and THAT did the trick. Feels great after a long day of skiing! Initially, I thought the 192 might cause the truck to run a little warm in the summer months, but that is not the case at all, so I leave it in there year round.
     
  10. BranndonC

    BranndonC 3/4 ton status

    Joined:
    Mar 18, 2002
    Posts:
    8,591
    Likes Received:
    0
    Location:
    Anaheim, Ca
    thanks for all the help guys. I'll look into one soon.
     
  11. pcorssmit

    pcorssmit 1/2 ton status

    Joined:
    Jan 2, 2001
    Posts:
    1,346
    Likes Received:
    0
    Location:
    Denver, CO
    With a TBI I would run a 195° thermostat. Also make sure you have the heat riser tube installed. I ran the heater hose on mine back to the water pump (instead of the rad) and capped off the radiator nipple, seemed to help also.

    Pete
     
  12. twenty_below0

    twenty_below0 1/2 ton status

    Joined:
    May 16, 2001
    Posts:
    436
    Likes Received:
    0
    Location:
    Haines, Alaska ...u.s.
    Now how does this work again?? I ran mine on another truck from the core to the intake and one to the water pump and NOTHING,..... wouldn't circulate.....how did you do this with yours and get it to work......maybe I missed something..........I would suggest for the main question to change the core it's really not to difficult and you'll be glad you did, the high thermostat is a must. Dont mean to spoog your post but I did the other suggestion and it just overheated the motor.....wouldn't want you to go through this. good luck
     
  13. pcorssmit

    pcorssmit 1/2 ton status

    Joined:
    Jan 2, 2001
    Posts:
    1,346
    Likes Received:
    0
    Location:
    Denver, CO
    I removed a plug from my water pump and ran the hose that used to go to the radiator to it (after threading in a nipple). A lot of passenger cars are like this, I think by Brother's '70 K5 may be this way too (or it could have been my other brother's '88 TA I was looking at). It seemed to help; I was daily driving mine for a few months during the winter a couple years ago, and with the fenders all hacked out and no inner fender wells, was having a hard time keeping any heat in the motor. I also advanced the timing like 8°, which helped.

    Pete
     
  14. BranndonC

    BranndonC 3/4 ton status

    Joined:
    Mar 18, 2002
    Posts:
    8,591
    Likes Received:
    0
    Location:
    Anaheim, Ca
    well i was just talking to my gilrfriends dad and he said changing the thermostat to a higher one would do absoltely nothing as far as increasing the temp of the air coming from the heater, it would just make it heat up faster, is this true?
     
  15. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    No, it's not true. The engine coolant will get hotter if there's a higher rated thermostat installed. This means that hotter coolant will be flowing through the heater core, so it can pump more BTU's into the cab. /forums/images/icons/cool.gif

    Think about it this way: Does it produce much heat when you first start it on a cold morning? There's coolant flowing through the heater core. /forums/images/icons/wink.gif The hotter the coolant gets, the more heat that you feel coming out of the vents. /forums/images/icons/shocked.gif
     
  16. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,977
    Likes Received:
    189
    Location:
    Roy WA
    Bought my car and noticed heater didn't really get warm. Found out no thermostat. Afterwards, plenty of heat. Not true that it doesn't matter.
     
  17. tomseviltwin

    tomseviltwin 1/2 ton status

    Joined:
    Dec 23, 2001
    Posts:
    2,065
    Likes Received:
    0
    Location:
    Utah
    That is wrong. A thermostat works by restricting the flow of water through the engine. If the thermostat is stuck wide open then the free flow of coolant would prevent the engine from retaining the heat that it does need. When my thermostat went bad on My wife's dodge caravan, you could run it up a canyon, open the radiator cap and touch the lukewarm coolant in the radiator. This was the same temp. water going through heater core and needless to say, the interior of car wouldn't heat up. Running too cool also prevents the computerized fuel injection from working properly too, (so I've been told) Also, when your heater just all the sudden goes cold, you've likely lost alot of coolant and ya better pull over and shut it down (amusing sister in law story) or your gonna sieze it up.
     
  18. BranndonC

    BranndonC 3/4 ton status

    Joined:
    Mar 18, 2002
    Posts:
    8,591
    Likes Received:
    0
    Location:
    Anaheim, Ca
    well right now my truck never gets hot, think my thermostat might be bad?
     
  19. K10ANDYKHAMNIC

    K10ANDYKHAMNIC 1/2 ton status

    Joined:
    Sep 17, 2001
    Posts:
    1,962
    Likes Received:
    0
    Location:
    Western CO
    replace it , its not hard at all /forums/images/icons/smile.gif
     
  20. daniel.wilson

    daniel.wilson Newbie

    Joined:
    Apr 16, 2002
    Posts:
    3
    Likes Received:
    0
    If you're going to change the core check out Eric's article on this website. I followed it last week and it was pretty straightforward. You probably wouldn't see any antifreeze outside the vehicle because GM was kind enough to install a system to absorb all of that coolant leaking from the heater core - they call it carpet padding. Seriously, pull the carpet back and see if your padding is soaked. Also, compress the insulation on the firewall right below the heater box. When mine went, that insulation was just saturated with coolant as was the carpet pad most of the way to the passenger seat.
     

Share This Page