Pushing coolant out of overflow at WOT only
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Pushing coolant out of overflow at WOT only Went out for some racing this weekend and the car for the first time ever was pushing coolant out of the overflow during runs. I can fill the radiator back up and it wont overflow during normal driving conditions just WOT pulls. Even driving for 30 min no problems. I checked the oil and its not milky/no white smoke from exhaust and doesnt overheat(unless WOT if i runs out of water) does it sound like my t-stat is getting partially stuck or my headgasket is blown?
car is a h/c ls1
car is a h/c ls1
Last edited by LT1 Trash; Nov 5, 2009 at 12:55 PM.
if you run it at op temp, is the coolant cold or is it heating properly? i would check this and make sure your rad/hoses arent clogged. check your t stat make sure it isnt stuck. this is where i would personally start 
Most likely all you need is a new radiator cap.
T-stat has nothing to do with it. If it sticks closed you will over heat no matter what your doing. If it sticks open you will over heat in city driving, but it will be fine on the highway.
Blown gasket....possible but not likely. Usually once a hole starts, you will have air getting pushed into the cooling system the whole time, whether at idle or WOT. It will just vary how much with rpm. But you probably wouldn't last much more than 15-20 minutes if a gasket is blown.
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T-stat has nothing to do with it. If it sticks closed you will over heat no matter what your doing. If it sticks open you will over heat in city driving, but it will be fine on the highway.
Blown gasket....possible but not likely. Usually once a hole starts, you will have air getting pushed into the cooling system the whole time, whether at idle or WOT. It will just vary how much with rpm. But you probably wouldn't last much more than 15-20 minutes if a gasket is blown.
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How many runs before you experienced the issue? Anything changed recently (parts, tune, fuel, etc)? Are you logging cooling system pressure? If not, pressure check cap and cooling system to know if system is releasing at specified pressure. Also, does system hold at that spec'd pressure or decay? If system is sealed to spec'd pressure, most likely lifting head under high load. What fuel? Back off timing especially around peak torque to reduce cylinder pressure.
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How many runs before you experienced the issue? Anything changed recently (parts, tune, fuel, etc)? Are you logging cooling system pressure? If not, pressure check cap and cooling system to know if system is releasing at specified pressure. Also, does system hold at that spec'd pressure or decay? If system is sealed to spec'd pressure, most likely lifting head under high load. What fuel? Back off timing especially around peak torque to reduce cylinder pressure.
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