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Cooling

What is the proper operating temp for a 5.7L, 1982 Chevy engine? The sensor is in the head on the left side of the engine. The temp gauge is a Stewart/Warner that shows actual temp not just a low and high with a space in between.

I don’t know, but it should be a little above the opening temp of a stock thermostat.

Depending on the ambient temperature, engine coolant temps can be anywhere from 210-225 degress F.

Tester

It depends on the thermostat set temp. If it is at 190, no matter where you take a temperature reading, it will be 190.

That 190 is the temperature at which the thermostat opens. Once it opens, it’s the job of the cooling system (radiator/fans} to keep coolant temperatures under control.

Tester

My experience is that the thermostat will open at 190, in this case, and the engine will maintain that temperature. I have done this with several model cars and the temperature that is read is the temperature marked on the thermostat.

Thanks for the help. I think I have either a bad/wrong thermostat or a defective gauge. The gauge tells me I am running at as much as 225 sometimes and yet I am not losing coolant. I suppose I could also have a bad water pump but if so it is not leaking. I have seen that in other applications where the impeller on the pump is erroded and so the flow is not adequate.

hbench

Tester is correct with his reply.

If the vehicle has a 190 thermostat in it, that’s the temperature the t-stat opens at, and will be the lowest temperature the engine operates at.

In practice, engine temperatures will rise much higher than the t-stat rating - often rising to the 220 to 230 degree range (and those temps are considered “under control”).