On my 04 s/c ss i had to change the heater hose fittings, they connect the heater core lines to the rest of the system, changing them out went fairly easily, but while bleeding the air out of the coolant i noticed, the car was not cooling down at all, the temp just kept rising. so i turned on the heat in the car just to see what happened, and it blew nothing but cold air. Im thinking something either blocked the heater core, or the thermostat is not opening all of the sudden.

Any other thoughts on what could be wrong, or advice on what to do?

Thanks

Andy

 

Hi `Andy, to me it sounds like a stuck, or bad thermostat.

Has it ever been replaced ? Check back to see what our experts member's post....Good Luck.

 

The thermostat is about a month old, i just pulled it and tried it in hot water, it opened and seems to be working ok.
My next question is there a way to clean out the heater core or just the lines without draining the whole system, i can get to the lines easy enough, would i be able to blow them out with air or something then fill the system back up?

 

Sounds like there was air in the system and the water pump was pumping air instead of coolant. My Lumina and Monte Carlo will do the same thing if air is trapped in the system.... the temp will rise and rise and rise.

Top off the radiator after it's cooled off (try adding coolant while the bleeder is open - that may force air out). Then run it again with the bleeder open. Maybe try revving the motor a bit - to get the water pump spinning faster. If the temp is rising higher than it should, shut it off, let it cool and add coolant again. Usually any air in the system of my car will bubble out into the overflow tank after the engine is shut off. I doubt it's a problem with the thermostat or heater core.

If the water pump wasn't pumping coolant, the engine would overheat but the heater core would be cool, because nothing would be getting pumped through it.

 

It's nothing but air. Top off the radiator, make sure to (with heavy gloves) squeeze the top rad hose (with bleeder close) once the TS opens, whatever amount of coolant needed pour into the reservoir not into the radiator, and open the bleeder valve. If you open the valve while the engine TS is still close you're introducing air in the system. Oh and turn the heater on full blast!

 

Im planning on letting the car sit all night and get nice and cool then ill bleed it in the morning.