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high temp on 95 suburban 454

Discussion in 'GM Powertrain' started by I_love_my_suburban, Jul 25, 2010.

  1. I_love_my_suburban

    I_love_my_suburban New Member

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    hey, my dad has a 95 suburban its a 2500 454, his temp gets up to 240-260f in a stand still, while moving its around 220-230f, we flushed the radiator, and it dropped the temp a little. is the temp supposed to be that hot? and if not what should we do?

    thanks for any help

    mike
    #1
  2. murdog94

    murdog94 New Member

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    Time for a T-stat... It should be no higher than 210 I would install a 185 T-stat... Also see if the clutch fan is engaging... Also Is it leaking/using coolant?
    #2
  3. I_love_my_suburban

    I_love_my_suburban New Member

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    im assuming the clutch fan is the fan right next to the radiator? if it is then yes it goes on. its not leaking, and i believe it uses it, we have open up the cap for the radiator to watch it move. thanks for the help.

    mike
    #3
  4. murdog94

    murdog94 New Member

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    What i meant by uses it is do you have to add any after it was filled? Because it is running nearly 30degrees hotter than it should.. Anything over 210degrees is damaging to the motor.
    #4
  5. hundojoe

    hundojoe New Member

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    Id put in a new water pump if your has a ton of miles on it, and like above thrown in a new thermostat, also see if the radiator hoses are collapsing pinching off coolant flow.
    #5
  6. tbplus10

    tbplus10 Moderator

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    Try "Water Wetter" too, the 7.4 engine doesnt take much to make it run on the hot side even when everythings working like it's supposed to.
    #6
  7. wkndrcr

    wkndrcr New Member

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    My 454 in my 90 had overheating issues, so I took it to a friend at the local repair shop and they used a "sniffer" to smell the rad coolant for hydrocarbons. It was alot higher then normal, indicating combustion gases were entering the coolant, the head gasket was leaking. There were no other indications of a head gasket issue, I even tried a t-stat and new waterpump beforehand. I replaced the head gaskets, surfaced the heads and the truck is perfect now!
    PS be careful when changing waterpumps because there is a reverse rotation for fuel injected engines and a forward rotation pump for carburated engine and they bolt up to either engine.
    #7
  8. I_love_my_suburban

    I_love_my_suburban New Member

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    we got a new t stat and the temp doesn't go past 210, so i am assuming that was the problem. we haven't had to add anymore coolant after the flush.

    thanks for the help murdog, and every one else.
    #8
  9. murdog94

    murdog94 New Member

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    Glad you got it fixed...
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