over heating

[jack]

I have a 99 rr 4.6 that over heats. At idle the heater blows cool air but if you rase the the motor the heater really puts out hot air. I have bled the rad flushed out the heater core. replaced the termo stat and heater core hoses. Can anyone help me ?

 

[Disco Mike]

It is obvious you don't maintain your fluid levels, your heater is blowing cold because you are low on coolant, you are low on coolant because of a leak, possibly head gaskets.
Sounds like it is time to start checking your truck over, and before driving it, today, fill and bleed your coolant system before you toast you engine.

 

[jack]

It is obvious you don't maintain your fluid levels, your heater is blowing cold because you are low on coolant, you are low on coolant because of a leak, possibly head gaskets.
Sounds like it is time to start checking your truck over, and before driving it, today, fill and bleed your coolant system before you toast you engine.

TH ANKS MIKE how ever my fuilds are fine and i have no leaks and the head gasket was just replaced and heads rebuilt so its not any those problems. I thought it might be the heater core if thats possible. Oh by the way I do maintain all my fiuld levels

 

[NhudeST]

If its reading Transmission Overheating, I am 100% sure you have to replace the Radiator. Its clogging the coolant at the bottom, preventing circulation throughout the coolant system.