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help! over heating BADD!!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by HZHRZ75BLAZER, Apr 13, 2002.

  1. HZHRZ75BLAZER

    HZHRZ75BLAZER Registered Member

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    I have a 75 blazer with 400 automatic. Having serious issues with over heating bad! i knew headers would run hotter but I am constantly overheating. have changed the thermo, water pump flushed system whats next. Might radiator be too small. Any help would be GREATLY appretiated.. Thanks all
     
  2. JungleBoy

    JungleBoy 1/2 ton status

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    Check your fan clutch, if you are running one. Are hoses good? I've seen them collapse. Try with out thermostat - does it still overheat? Check to see you have good water circulation (be careful how you do this, opening the radiator when hot "can be treacherous"). You can wrap your headers, too to keep engine compartment heat down. Is it possible you have a lot of junk in the block or radiator that you didn't get flushing? You might work toward a good 4 row radiator and a 28k GVW trans cooler, but in the meantime check each component.
    Good luck
    JB
     
  3. Thunder

    Thunder 3/4 ton status

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    Take the radiator to a radiator shop and have them clean it out. There are probabally a bunch of clogged tubes. The comercial radiator flushes do little or nothing to disolve corrosion in the radiator or un clog it.
    Also as said, Check the fan clutch.
    The headers make the engine compartment a little hotter but have nothing to do with your engine overheating unless they are clogged up with something and restricting the exahust flow. But that doesn't seem to likely.
     
  4. BigTex

    BigTex 1/2 ton status

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    Having the headers alone will not cause the engine to over-heat. Yes, the engine compartment may be hotter, but it would not cause an overheating problem. I'd do what everyone else suggested. Check your timing also. Does your fan have a shroud? Also, make sure your new thermostat is working properly. Your radiator may very well be too small but even if it were too small, it wouldn't necessarily overheat if the radiator is in good shape.
     
  5. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    i second EVERYTHING jungleboy said. also i second(again) the headder wrap. i know what i am about to tell you is about a honda, but we wrapped my buddies headders on his CRX and it ran a lot cooler. yeah, smaller engine compartments and all, but it does help. and supposed to make a bit more power.
    grant
     
  6. Blazer79

    Blazer79 1/2 ton status

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    What's the correct way of installing a thermostat? spring side up and check ball down or spring side down and check ball up?

    Also, how does timing cause overheating? Too advanced and why?

    Thanks.
     
  7. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    Pointy end up is the correct way to install a thermostat, techinical description, huh?
     
  8. HZHRZ75BLAZER

    HZHRZ75BLAZER Registered Member

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    Thanks for all the suggestions and help. Going to have radiator cleaned out. I agree, I did not think the headers would make it over heat, but running out of options. Thanks again.
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    You might also ask around and see if you can have the radiator flow tested before having it cleaned. The local radiator shop/wrecking yard will flow test them for free as long as you bring it to them. I had one flowing at half capacity, and it would overheat (250*) within 7 minutes of starting the vehicle.
     

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