Overheating Problem
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From: Charlotte, NC
Overheating Problem Ok, a friend of mines car is a 95 383 car, heavily modified, full LT4 topend all ported, GM847 cam, lots of work. For some reason it keeps wanting to overheat, and it doesnt just do it all the time, its only when its being driven, it can idle for hours and not overheat, it went on the dyno and didnt over heat even turned it to 7K and no problems. But the minute you take it down the road the temp shoots up. It has no thermostat in it and it has a mezier water pump, fans are not a problem, they kick on when they should. Coolant has all been replaced and vacumed to take out the air since there is only one bleeder left. Any ideas?
assuming there is no headgasket problems make sure the fans are going the correct way first and has full voltage, and make sure the waterpump has full voltage.
if not it is one of two things.
because the radiator cannot dissipate enough heat under a load (too small or restricted). or without a thermostat the coolant is going through the radiator too fast before it can dissapate enough heat (try a 160 t-stat).
if the t-stat doesnt work try 'water wetter' first. it does work well.
if not it is one of two things.
because the radiator cannot dissipate enough heat under a load (too small or restricted). or without a thermostat the coolant is going through the radiator too fast before it can dissapate enough heat (try a 160 t-stat).
if the t-stat doesnt work try 'water wetter' first. it does work well.
Thread Starter
TECH Fanatic
iTrader: (10)
Joined: May 2005
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From: Charlotte, NC
ok, i was thinking the same thing with the thermostat, because it is an electric water pump it is pulling the same amount at all times rather than a cam driven stock pump which will fluxuate with the rpms. My other question though is that if its pumping too fast then this would be shown worse at idle wouldnt it? That was the next thing we were going to try though, the 160 thermostat.
try the stat first and i swear by water wetter. but at idle there is no load what so-ever so it can overcome a poor radiator.
if it overheats at idle it is normally a fan problem, at speed it is normally a radiator problem.
good luck.
if it overheats at idle it is normally a fan problem, at speed it is normally a radiator problem.
good luck.
Check to make sure the mezier is wired right and not pumping backwards. That would work at idle OK but not under load.
I'd do the water wetter anyway. If you aren't in a cold area, run straight water with a couple ounces of water wetter in it. Depending on the cold, add antifreeze as needed. Water conducts heat way better than antifreeze. Use distilled or deionized water.
Jim
I'd do the water wetter anyway. If you aren't in a cold area, run straight water with a couple ounces of water wetter in it. Depending on the cold, add antifreeze as needed. Water conducts heat way better than antifreeze. Use distilled or deionized water.
Jim
