Engine overheating

**joearvelo1987** · 08-25-2015

Hey guys, I have a 2006 grand prix gt 3.8 SC. My engine has been overheating and I thought it might be the thermostat, so I replaced it the upper hose and radiator cap. The one thing I could not find was the drain plug to completely drain the system properly and I need to know how to go about bleeding the system of any air that might be in the line. I want to try these things before I replace the radiator. Some of the symptoms I'm having include no heat with the heater on high, it feels like the a/c is blowing and it overheats into the red within five minutes of driving. The upper hose that goes from the thermostat to the radiator gets hot, and I'm sure that the thermostat is facing the right direction. I'm kind of a noob at this so forgive me is this is a little jumbled.

Thanks All!

**Scottydoggs** · 08-25-2015

the heater core is air bound, take both hoses off the alt bracket, then put a garden hose to either hose and flush it, then do the other hose.

how to flush coolant.

remove the t stat, put the t stat housing back on, take the upper hose off the radiator, then push it down to the ground to a bucket or let it fly.

get your garden hose out, put it in the rad turn it on, then fire up the car, let it run till clear water pumps out the top hose.

then turn the hose off, run the car till no more water comes out the upper hose. then turn it off.

put your t stat back in, with new gasket, the upper hose back on.

now take 1 gallon of full strength green antifreeze, not the 50/50 crap. ( parts store cheap green is fine to use) dump the whole gallon in the radiator, fire up the car, fill the rad with hose water till its full. top as needed till its ready to be bled of air. it will burp and take coolant as the water in the block warms up the t stat opens up for a few seconds till cold coolant hits it and it shuts again.

now to bleed the air out, let it idle rad cap off till the fans turn on, (when the fans are on the temp is over 195 deg, the t stat is wide open) then open the bleeder screw on top the t stat housing a few turns till a steady stream of coolant comes out the hole, shut the screw, top off the rad. cap it.

done.

while flushing the system, if its not pumping out the upper hose at a good rate, the pump maybe rusted apart, or the rad maybe clogged up.