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.

My rig is heating up

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by bigdaddy89, Feb 20, 2001.

  1. bigdaddy89

    bigdaddy89 1/2 ton status

    Joined:
    May 18, 2000
    Posts:
    422
    Likes Received:
    0
    Location:
    Phx, Az
    While out on a highway trip on Monday my blazer got into the red when I came to a stop. Of course it cooled back down when the truck got some air moving throught the radiator again. I pulled over to check and see what might be the problem and noticed that the overflow tank had overflowed. I have just replaced the water pump and thermostat in the last 2 weeks. Do you think this might be a radiator problem? It is the original and never has been roded out. It looks as if it might be a little corroded inside. It is a 1989 with a 350fi and auto trans. It has 117.000 miles. I can put a new one in, but I want to be sure this might be the problem. Does anybody know what the orig. core size this is, and if I can upgrade to a better one? Thanks for the reply.

    GOT ROCKS?
     
  2. muddin4fun

    muddin4fun 3/4 ton status

    Joined:
    Feb 19, 2001
    Posts:
    5,644
    Likes Received:
    0
    Location:
    N Texas
    how fast did you have to go before it started to cool off? you might look at the radiator and also make sure the clutch fan is working and make sure your fan shroud is in ok shape

    [​IMG] Keep your feet dry [​IMG]
     
  3. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    Don't for get to look at the obvious...how's the radiator cap? if it doesn't hold presure the boil temp is lower and once it boils the coolant become airrated and looses it's cooling effectiveness. Also did you put the same temp thermostat in or did you change the temp? Sometimes putting a lower temp thermostat will cause an engine to run hotter. The coolant will move too fast through the system and fail to pickup/shed as much heat. On a FI vehicle your always best staying with the Temp it cam with from the factory.

    Diging it in the dirt with my K5's
    Grim-Reaper
    <A target="_blank" HREF=http://grimsk5s.coloradok5.com/>http://grimsk5s.coloradok5.com/</A>
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    If you haven't changed any specs on the vehicle, or haven';t started using it differently (towing, etc) then stick with the factory radiator size. I threw a known good 2 core in my truck with 350, 195 t-stat, manual trans, and engine oil cooler, and have no problems whatsoever with it overheating. From experience, the only way you can tell if a radiator is working properly is to have it flow tested. Sometimes recores are cheap enough to be feasible, but a lot of times, new radiators are the same price as getting recored.

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  5. Stoopalini

    Stoopalini 1/2 ton status

    Joined:
    Oct 17, 2000
    Posts:
    999
    Likes Received:
    0
    Location:
    Austin, Texas
    It sounds to me that your clutch fan is toast. I would replace that 1st ............. unless you have done something the other guys have mentioned, like replaced your thermostat with a non-factory one?

    Good luck,

    Thomas.

    -- '84 K5 Blazer --
    <A target="_blank" HREF=http://Stoopalini.coloradok5.com>http://Stoopalini.coloradok5.com</A>
     
  6. bigdaddy89

    bigdaddy89 1/2 ton status

    Joined:
    May 18, 2000
    Posts:
    422
    Likes Received:
    0
    Location:
    Phx, Az
    I think I will try replacing the cap to see if that might help out. I have a 180 thermo in it right now, because I am running a Hypertech chip. This problem just started. I did notice today that I have a very slight leak on the cap neck. I do tow with this vehicle and I am running 35x14.50 SSRs w/ 3.73 gears.Grim, Do you know what core I might have, and if I would be able to upgrade to a better one instead of having the leak fixed and it roded out?

    GOT ROCKS?
     
  7. DMK

    DMK 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    757
    Likes Received:
    0
    Location:
    CINCINNATI, OH
    I f your truck is only overheating at stops it is more than likely your fan clutch. Or fan shroud problems. A bad radiator cap would cause overheating right away not just at stops. I assume you have an 89 fullsize. Should be 3 core radiator.
    Look for a radiator shop in your area, I saved over half on the price of a 3 core and got a 4 core. And it will fit with no mods because the jugs are the same size. My 4 core was 159 with tax brand new.
     

Share This Page