getting hot

[FlamespikeMST1]

3.4 firebird has a heating issue.
my temp gauge would go sky rocketing during regular warm up, then go back down to regular operating temperature.it would do this throughout my trip.

While the temp gauge was high, i would turn on the heater and all i would get is cold air shooting, when back to normal operating temperature, i would get hot air.

i already did a radiator flush and replaced the thermostat, does anyone have any ideas what is causeing this, and how i can fix it?

[Question]

Did you replace the sending unit? How does it run when it sky rockets? Is there a noticable difference? How hot are we talking here? Im wondering if it is not a heating problem, but the gauge giving false readings.

[FlamespikeMST1]

well i was thinking the same thing but would it cause the radiator fluid to flow out of the overflow?
when the temp sky rockets its 3/4 of the way full
no noticeable change, just the normal sluggishness of a 3.4
and if the the gauge is giving false readings would that effect the heater from not sending hot air?
ill try my damndest to get a small vid or a few pics on here asap
thanks for the help in advance

[FlamespikeMST1]

TTT

[gergwheel]

you are either low on coolant, or you have an air bubble in the system

[Coriya71]

Yup, my vote is for air/low coolant too. When your running really hot, your pumping an air pocket, thats why your heater is blowing cold. When it goes back to normal temps, the coolant that you do have in there is cooling the engine and transfering heat in the heater core, making the heater heat. It'll look like its full, but make sure your bleeding all the air out of the system.

[FlamespikeMST1]

thanks to all, its was a leak from a broken gasket in the waterpump, not enough coolant, and horrible smell, lol thanks though