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Hummer H3For the Hummer driver who wants the rugged look and off road capabilities of the Hummer, but in a smaller size and with a more fuel economy friendly engine.
Did you check system temps with IR? Did you verify thermostat operation?
The thermostat should begin to open at 194°. Connect scanner, check coolant temp(make sure below 194°) start engine, let idle, & monitor coolant temp, you should see a drop in coolant temp around 194°. Watching the coolant temp rise, you should see a drop in coolant temp when the thermostat starts to open, letting you know the thermostat is working properly.
My car is currently at the mechanic and i got busy with work so i havent been able to collect it yet, I'll check once i get it back tomorrow hopefully.
it's a new thermostat so i do hope it's working fine.
Did you check system temps with IR? Did you verify thermostat operation?
The thermostat should begin to open at 194°. Connect scanner, check coolant temp(make sure below 194°) start engine, let idle, & monitor coolant temp, you should see a drop in coolant temp around 194°. Watching the coolant temp rise, you should see a drop in coolant temp when the thermostat starts to open, letting you know the thermostat is working properly.
So, I checked the thermostat function and it seems to be ok - although it seems like the thermostat opened at ~190°F. I let it idle for quite a while but the temperature stopped rising after around 190F and stayed like that until i started driving and it rose slowly. Cruised back home and temp went up to 221F at some steep roads but the outside temperature was around 110F anyway (at night, mind you). The temperatures do drop back down as the load on the endine reduces but yes, the problem seems to persist.
i just changed my thermostat because my gauge went all the way to H when sotting in the sun with the ac on. The thing still sits at 3/4 even when hot. i thought it should at least drop back down then come up idk. Acdelco one too
So, I checked the thermostat function and it seems to be ok - although it seems like the thermostat opened at ~190°F. I let it idle for quite a while but the temperature stopped rising after around 190F and stayed like that until i started driving and it rose slowly. Cruised back home and temp went up to 221F at some steep roads but the outside temperature was around 110F anyway (at night, mind you). The temperatures do drop back down as the load on the endine reduces but yes, the problem seems to persist.
Did you check coolant system with IR?
If your temperature is fine until you drive, the most likely issue is coolant flow. A coolant flow issue can be caused by a faulty thermostat (not opening fully), a damaged water pump impeller or loose/worn belt/tensioner, or a restriction in the radiator/hoses.
Did you check coolant system with IR?
If your temperature is fine until you drive, the most likely issue is coolant flow. A coolant flow issue can be caused by a faulty thermostat (not opening fully), a damaged water pump impeller or loose/worn belt/tensioner, or a restriction in the radiator/hoses.
I unfortunately dont have access to an IR atm so havent been able to check that.
however, the other things you mentioned have almost all been checked/replaced - thermostat (seems to be working), new water pump, replaced tensioner and belt in good condition, radiator cleaned.
And even when cruising at 80mph or so, the temperature remains stable. The only time it starts to increase is while accelerating and that too is very gradual but it does get up there.
I unfortunately dont have access to an IR atm so havent been able to check that.
however, the other things you mentioned have almost all been checked/replaced - thermostat (seems to be working), new water pump, replaced tensioner and belt in good condition, radiator cleaned.
And even when cruising at 80mph or so, the temperature remains stable. The only time it starts to increase is while accelerating and that too is very gradual but it does get up there.
IR gun is a great tool to diagnose!
The gauge/scanner is computer driven and can only display the reading provided by the computer based on information it receives from the sensor. Sensors have been known to grow tired. Overheating is caused by more heat being produced than can be dissipated by the cooling system and are mostly due to insufficient coolant flow through the radiator or insufficient cooling air through the radiator or a combination of both. It is possible coolant system becomes blocked with bubbles of combustion gas and can accumulate around the thermostat and disrupt the proper operation, and when a cylinder head gasket begins to fail those gas bubbles can become excessive. If they can't harmlessly rise to the top of the coolant level they can build up and restrict flow and displace coolant and cause hot spots in the cylinder head.
The gauge/scanner is computer driven and can only display the reading provided by the computer based on information it receives from the sensor. Sensors have been known to grow tired. Overheating is caused by more heat being produced than can be dissipated by the cooling system and are mostly due to insufficient coolant flow through the radiator or insufficient cooling air through the radiator or a combination of both. It is possible coolant system becomes blocked with bubbles of combustion gas and can accumulate around the thermostat and disrupt the proper operation, and when a cylinder head gasket begins to fail those gas bubbles can become excessive. If they can't harmlessly rise to the top of the coolant level they can build up and restrict flow and displace coolant and cause hot spots in the cylinder head.
I'll try to get my hands on an IR gun.
My H3 has never once heated or had any cooling system related issues for more than a year, not even as little as a a drop in coolant levels. Are you suggesting it could be the head gasket? Isn't that cause by heating? And i serviced the car around 50mi ago and the oil was clean too. No signs of any head gasket leaks in any way
My H3 has never once heated or had any cooling system related issues for more than a year, not even as little as a a drop in coolant levels. Are you suggesting it could be the head gasket? Isn't that cause by heating? And i serviced the car around 50mi ago and the oil was clean too. No signs of any head gasket leaks in any way
