1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

thermo saying HOT when driving only?

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Old 04-01-14, 06:08 AM
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Doritos & Dual Sports

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thermo saying HOT when driving only?

when idling it holds perfect temp, when i start driving it gets hotter to the dangerous level but then i stop and it cools itself off again? have an e fan hooked up and i just leave it on after it gets to it's normal operating temp. even when rolling around 45 or so and i put it in neutral it stays "hot" until i stop. Engine appears fine and hasnt overheated and shut itself off... im thinking just bad thermo, any insight? running a ported intake manifold which blocks off the coolant from entering it, and a mikuni carb. wasnt doing this before i deleted emissions and put the carb on and headers...ect. didnt mess with the cooling system though
Old 04-01-14, 04:21 PM
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Is your Efan blowing the correct direction?



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Old 04-02-14, 05:38 AM
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Originally Posted by Kentetsu
Is your Efan blowing the correct direction?



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sitting behind the radiator pulling through it (front to back direction), im almost positive this is correct?
Old 04-03-14, 06:15 AM
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replaced the thermo and flushed my radiator. my gauge is now reading only slightly hotter than it should, noticable cooler (guage wise) than what it was. Gonna install an aftermarket gauge. That being said does anyone know what 12a's normal operating temp is suppose to be?

I think my water pump might have gone up as well
Old 04-04-14, 12:43 PM
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thanks for all the help -___-
ordered a new water pump and will flush out the Entire system when i have it apart installing. Anyone have rust on the piece you remove to get to the thermostat? mine was all rusted up and had chunks coming off... thinking that might be stopping the flow
Old 04-04-14, 01:34 PM
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If you have beehive it's a good time to do the orings and associated coolant hoses there as well.
Old 06-10-14, 06:34 PM
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Make sure your water pump belt isn't slipping...
Old 06-11-14, 01:08 AM
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The other obvious thing to check is that your radiator could be clogged up, such that idle engine heat can be shed properly, but once you get it rolling there's not a lot of coolant flowing through a clogged radiator - no matter how fast the e-fan is turning - it's not going to be able to cool the temps generated from an engine running faster.

If you haven't done so already, you should pull the radiator and have a good radiator shop unsolder the top tank and rod it out. You may find that brings the temps down considerably.

Also - there's no temperature 'fail-safe' on these cars; if you overheat it and the engine shuts down - it's dead right there. It will never restart because you cooked it - so do the right thing and get the cooling system fixed and working properly.

Remember: 1/3 engine cooling from adiabatic (air around the engine core), 1/3 cooling from radiator, and the other 1/3 cooling from the oil circulation system & cooler (beehive or FMOC). HTH,
Old 06-11-14, 06:51 AM
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Water pump isn't skipping, and I just put the radiator back in from having a shop open it up and clean it. Said a little junk came out... But was very clean and shouldn't have been giving me issues.... Ugh
It's shut off on me multiple times during the day when the sun is out. I give it about 5 mins and then she starts back up. If I dont, she won't start.
No fail safe ? Are you sure? Seems it's over heating and shutting off, then starting back up after it's cooled off a little
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