gotta be a pain
overheating after coolant change
Thread Starter
Instructor
Joined: Jul 2002
Posts: 114
Likes: 0
From: college park md
overheating after coolant change
I just changed the coolant on my 96 LT1. I drained the radiator and engine block. I refilled with coolant and water. I ran the engine and let the temperature come up 200. As i was waiting for the fan to kick on, the temp hit 240 and i can hear the resovoir tank boiling and the radiator was cool as ice. Can someone tell me what i need to do??
Melting Slicks
Joined: May 2005
Posts: 2,730
Likes: 1
From: Atoka Oklahoma
St. Jude Donor 06
Originally Posted by aboatguy
Did you burp it ?
There are air bleed valves on your engine that need to be opened when you are filling your cooling system.
There are air bleed valves on your engine that need to be opened when you are filling your cooling system.
I am not real crazy about the location where they put the bleeder either 
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Pop the cap off the tank and let the engine run a bit...squeeze the hoses around the water pump to move the coolant around and help push out some of the air, then top-off the coolant in the tank. Open the bleeder on the hose next the water pump to bleed out the rest of the air then top off the tank one last time and put the cap back on, then fill the reservoir tank up so it is in between the warm and cool mark. You should be good to go at that point.
Le Mans Master
Joined: May 2005
Posts: 7,337
Likes: 2,266
From: Central Maryland
As has been noted by others here, you need to bleed the air out of the system as you refill it. There should be a bleeder screw on the thermostat housing, and another on the driver's side of the throttle body. Open these screws as you're refilling the system, and close them only when you get a solid stream coming out with no air bubbles. Be sure to pack rags under them to keep the Opti from getting douched during this process.
Be well,
SJW
Be well,
SJW
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
I had exact same problem a few weeks ago when my heater valve blew up. I filled the system while running the engine, and bled the air out of the screw located on thrmostat housing.
-Drove the car around and temps still above 240. I let engine cool down, and topped off the resorvoir with coolant/H2O. She took about a gallon.
I repeated the above step until the resorvoir remained constantly "full". Maybe not the smartest way, but it works. What I learned was that even when coolant starts to come out of bleeder screw, that is not a guaranty that your system is at capacity...
-Drove the car around and temps still above 240. I let engine cool down, and topped off the resorvoir with coolant/H2O. She took about a gallon.
I repeated the above step until the resorvoir remained constantly "full". Maybe not the smartest way, but it works. What I learned was that even when coolant starts to come out of bleeder screw, that is not a guaranty that your system is at capacity...
Safety Car
Joined: Apr 2004
Posts: 4,532
Likes: 7
From: Lahaina Hi
When you open the bleeder on the thermastat put a big towel down so the opti doesn't get wet. 
The radiator is to low
so it is a pain to get the water up to the proper level to get all the bubbles out.
Another chevy after though.
That is why you have the square bars in the front to hold the radiator in .The radiator was an after thought.
The radiator is to low
so it is a pain to get the water up to the proper level to get all the bubbles out.Another chevy after though.
That is why you have the square bars in the front to hold the radiator in .The radiator was an after thought.
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Racer
Joined: Nov 2005
Posts: 456
Likes: 3
From: Sumner Texas
Continue removing the radiator cap every time the engine completely cools and topping off with antifreeze/water mix. Continue to do this every time the radiator COMPLETELY cools until it is full when you open it.
Good luck,
Good luck,
Le Mans Master
Joined: May 2005
Posts: 7,337
Likes: 2,266
From: Central Maryland
Originally Posted by MBDiagMan
Continue removing the radiator cap every time the engine completely cools and topping off with antifreeze/water mix. Continue to do this every time the radiator COMPLETELY cools until it is full when you open it.
Good luck,
Good luck,
There is a specific cooling system refill procedure in the Factory Service Manual. I highly recommend that any Corvette owner who ever lifts his/her own hood should have a copy of the FSM. Follow the procedure in the FSM, and you should have no problems.
Be well,
SJW
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
One important thing they always told us at the dealership i worked at was not to run the car with the bleeders open. I see alot of guys do this and it can actually introduce air into the system if your not real careful.
I open the bleeders, fill the car, then close the bleeders and it should be good to go. Sometimes I'll run the car with the cap off but its not required.
I open the bleeders, fill the car, then close the bleeders and it should be good to go. Sometimes I'll run the car with the cap off but its not required.
