03 hemi temp gauge rising, not heat

[catbee]

03 ram hemi temp gauge will rise as heat shuts off blowing cold air.....coolant is overflowing through overflow tube....whats causing this?

[BleedDodge]

It's pressurizing somewhere.

[catbee]

thanks bleeddodge....they just changed thermostat and pressurized....give me a possible example if you could

[BleedDodge]

Maybe the new thermostat was put in backwards? Did you replace it before or after this problem started?

Why would the thermostat need to be replaced on a 2003 truck? Did something else happen?

[catbee]

maybe backwards...i brought it back tonight...waiting for result tomorrw....nothing happend b4.....could be headgasket?...your thoughts?....thanks man

[fredjacksonsan]

You could also have some air locked in/near the heater core. If the problem persists once you get it back, try parking with the front end uphill to let any air out; let the thermostat cycle a couple times and keep an eye on the radiator level. If there's air you'll probably see some big bubbles come out, and the radiator level go down.