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stumpped: Temp gauge RED zone ! Heating pblms !! 700 1985

B230F '85 740

Temp gauge in RED zone !
{ real hot-heat streaming out of defrost vents }
{ heater fan on "4" , gauge does not drop out of red zone !}

Stumped !!

I have:
Replaced original 92 deg. thermostat. No change.
Replace & tentioned fan belt & alt belt. No change.
Pulled thermostat out completely, ah.. better gauge in middle..
Put new 92 deg. thermostat back in, RED zone again !

Put in new (used) viscous fan assembly. No change.
NB. Electric fan has been rusted & siezed for years...thus not a factor.

Can't see any swirling of liquid in rad fluid 'hotdog' shaped filling container.
Hoses are not collapsed & have firm pressure when car on.


Rad fins do not seem to be plugged with insects, but will hose these out.


Could it be water pump or clogged rad ?

Voltage regulator ???

stumpped!








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    stumpped: Temp gauge RED zone ! Heating pblms !! 700 1985

    Any oil in the coolant? Coolant in the oil, milky white goo? If so, could be a head gasket.

    If not, with no other indications of overheating, I'd suspect the wiring, gauge or sensor, in that order.








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    stumpped: Temp gauge RED zone ! Heating pblms !! 700 1985


    Insects and minor problems aren't going to cause your brick to heat unless you are running it hard, like WOT up a 20 degree incline for 20 minutes or something.

    Sounds like a failed water pump, although the fact that hot fluid is moving to the core in the dash would seem to rul that out (you did check the pump first, right?).

    Ah, wait, I know what it is. You didn't replace the t-stat properly, or you didn't fill up the head first and now have a giant air pocket in there that prevents the t-stat from getting heated up (no liquid against it). if the t-stat doesn't get hot it won't open, and if it doesn't open hot fluid will simply vacate the head and you will overheat quite quickly.

    Take off the t-stat cover, fill up the head as far as possible without overspill, fill up the rest of the system as far as possible (hold the hose to the t-stat housing up to get it nice and full), quickly connect the housing to teh head and bolt it down (put paper towels undeneath to get and overflow). Start and run normally.

    BTW, if the car even goes borderline red I would suggest you turn iut off immediately. You are going to warp the head if you aren't careful.

    -rt








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      stumpped: Temp gauge RED zone ! Heating pblms !! 700 1985

      This heating problem started suddenly.
      No coolant leaks.

      Thermostat installed with little vent hole pointing upwards.
      Did not fill up hose with fluid. Topped up refill container.

      How does one check the water pump when it is in the circuit ?
      With engine on, Pressure in bot top & bottom hoses very firm( can feel water running).

      Strange!








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        stumpped: Temp gauge RED zone ! Heating pblms !! 700 1985

        Are both your upper and lower rad hoses hot? Normally when the thermostat opens, the lower hose will be cool to the touch. Wonder if you got a bum theromstat. Strange for sure. Also, try turning on your heater on high with the fan on high. Your heater is just a small radiator and see it that holds the temp down. If it does, your water pump is probably circulating coolant.

        bl








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          stumpped: Temp gauge RED zone ! Heating pblms !! 700 1985

          Here's my two cents:
          Clogged radiator. Feel over the surface of the radiator, fan off, hehe, to detect cool spots. Head off to the local salvage yard if you don't feel a nice hot surface.

          If the car is a turbo, try this: Bad thermostat--in the air cleaner! If that little cylindrical dohickey goes, the air cleaner gets pre-heated air, which is then cooled by the intercooler--meanshile your radiator, which sits behind it, thinks the ambient temp is like 195 degrees.

          Been there.

          -Steve








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            Heater fan on High :does NOT help drop Temp Gauge reading !! 700 1985

            This 740 in NOT a Turbo.

            The heater fan on HIGH (setting 4) does NOT drop the temp gauge value.

            With the 'bum' thermostat IN , the brick gauge starts cold, is in middle within gauge. In 3 km it is up at the edge of the red zone, then bumps back down a bit then with more driving, hits into the red zone.

            Yes I think I got a bum thermostat.
            BUT must be more than that .... ??

            Still stumpped !!







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