I have bled two engines so far. On the thermostat or just above it you will find a bolt ( I believe Will S is correct of it being about 7mm), just turn it or even remove it and fill the radiator until it flows out of the hole. But look near or just above the thermostat for the bleeder screw/bolt etc.
I have a 2003 Pontiac Sunfire we changed the thermostat, how do you bleed the coolant system?
No, not the butterfly valve at the bottom of the radiator Jay. That will just drain the coolant out of his car.
To bleed air out of the coolant system do the following:
A) On a stone cold engine make sure the radiator is full of coolant and fill the coolant reservior up to the max cold fill point.
B) Put the radiator cap back on and seal it if you have not already
C) Start your engine, let it run until it gets up to normal operating temperature.
D) Locate the thermostat housing. It is on top of the intake manifold. The upper radiator hose goes into it. On top of the thermostat housing you will see a valve with a little twist nut on it. Grab a screwdriver and a rag. Twist the little nut on top of the thermostat housing with the screwdriver slowly. You will hear air hissing out. As soon as you see a trickle of coolant begin to seep out of it, close it with the screwdriver and clean up the coolant with the rag.
Rev the engine a few times. Make sure the coolant reservior is still topped off. Bleed the system with the screwdriver yet again with the same procedure. If coolant begins to trickle out right away, your system is bled well. If more air hisses out before coolant begins to trickle, continue the bleed procedure until only coolant trickles out immediately.
The goal is to get the air pockets out of your system that get superheated. Hope this helps.
I have a 2003 Pontiac Sunfire we changed the thermostat, how do you bleed the coolant system?
Never on any vehicle bleed it when its running. Locate the bleeder, should be a 7mm bolt, loosen it with radiator cap off and radiator full and wait for the coolant to come out at a steady pace, whatever you do, dont do that when it's running.
The butterfly valve at the bottom of the radiator.
Turn that by hand until the water/coolant begins to drain out. If you do that when the car is cold, there shouldn't be much in the block.
You should have examined all your hoses already. If they have never been replaced, they are probably not good. 5 years is a long time on a hose.
normally there is a small brass screw that i open when I'm filling the system when it runs out of there its bled pretty good,but i did have this one nightmare engine i replaced the head gasket at lest 5 mechanic shops worked on it we never could figure it out
There should be a bleeder screw either by the radiator or by the engine block. It is just a little screw with a hole in the top of the screw. loosen it while the car is running when you get water and not air tighten it back up.
Hope this helps
