1991 Chevrolet K1500, 4.3 engine. Engine temperature shoots up pretty quickly upon starting. Would think that if it was the thermostat, it would take a bit for the temperature to come up. Your thoughts?
Head gaskets, thermostat?
- Thread starter otis24
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Are you certain that the dash gauge is accurate?
Although I have heard of 4.3 head gasket leaks, it's not a common problem. If there's air in the system the temp will rise quickly. If the block is busted from freezing maybe too.
Are you saying that this fast warm-up is followed by overheating?
Any thermostat should be fully closed during warm-up, so it wouldn't matter. Slow or no warm-up would mean thermostat is stuck open.
Very easy to remove thermostat on these to test or just replace.
Any thermostat should be fully closed during warm-up, so it wouldn't matter. Slow or no warm-up would mean thermostat is stuck open.
Very easy to remove thermostat on these to test or just replace.
When the key is off and the vehicle has sat for a while, the temp is staying up. Makes me think it is a guage or coolant temp sensor issue. Er, I should say that the guage reading is staying up.
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Originally Posted by otis24
1991 Chevrolet K1500, 4.3 engine. Engine temperature shoots up pretty quickly upon starting. Would think that if it was the thermostat, it would take a bit for the temperature to come up. Your thoughts?
If it were a newer vehicle, I would connect a code reader that does live data, compare that to the dash gauge that you are presumably looking at.
1991 Chevrolet K1500, 4.3 engine. Engine temperature shoots up pretty quickly upon starting. Would think that if it was the thermostat, it would take a bit for the temperature to come up. Your thoughts?
If it were a newer vehicle, I would connect a code reader that does live data, compare that to the dash gauge that you are presumably looking at.
Radiator is full. No apparent sign of overheating. Didn't run it long enough today to get the temperature up to check the heater.
Probably a bad Coolant Temp Sensor. There's probably two....so make sure your replacing the one that connects to the dash gauge. There not expensive but you can test it before replacing it. Check YouTube for testing. I'd start spraying it down with penetrating oil now.
Typically the sender you want as a single , one for FI is 2 wire.
It would take about 15 minutes from a cold start to get hot. If it's going up faster than that it's likely the gauge or sender. Check the actual temp with an IR gun.
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