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71 Chevy, Engine overheats
- Thread starter glb
- Start date
eugene68
Member
Quick question,
when you say you are losing antifreeze out your overflow, do you you have your overflow hooked up to a recovery tank? or is it just dumping out on the ground?
the overflow was designed to let your coolant overflow when it gets hot, and then as the engine cools it actually sucks the coolant back into the radiator.
now if your engine continually overheats I would look at your thermo-clutch on your fan blade if you are running one.. see if it is good,
squeeze the top radiator hose after it is warmed up, see if you are getting some flow.. look at your radiator with the cap off engine cool, just started, rev the gas a few times you should see it surge as you rev the engine,once the engine is hot enough to open the thermistat, watch the eyes..
check you belt to your waterpump, make sure it is not slipping,
check you fins on the radiator they tend to get full of bugs, dirt, etc... closed off.. a good powerwash does wonders.. why you are at it clean you engine off too.. a clean engine actually runs cooler..
a flush of the cooling system wouldn't be a bad idea..
it that does not help, check your timing,, if it is off it can make it run hot...
if your engine carb mixture is too lean it will make it run hotter..
not to mention burn a valve...
other things a slipping torque converter or clutch will make it run
hotter..
hope some of these ideas help you ..
if you are running a 2 or 3 core radiator consider going to a 4 core.
eugene68
when you say you are losing antifreeze out your overflow, do you you have your overflow hooked up to a recovery tank? or is it just dumping out on the ground?
the overflow was designed to let your coolant overflow when it gets hot, and then as the engine cools it actually sucks the coolant back into the radiator.
now if your engine continually overheats I would look at your thermo-clutch on your fan blade if you are running one.. see if it is good,
squeeze the top radiator hose after it is warmed up, see if you are getting some flow.. look at your radiator with the cap off engine cool, just started, rev the gas a few times you should see it surge as you rev the engine,once the engine is hot enough to open the thermistat, watch the eyes..
check you belt to your waterpump, make sure it is not slipping,
check you fins on the radiator they tend to get full of bugs, dirt, etc... closed off.. a good powerwash does wonders.. why you are at it clean you engine off too.. a clean engine actually runs cooler..
a flush of the cooling system wouldn't be a bad idea..
it that does not help, check your timing,, if it is off it can make it run hot...
if your engine carb mixture is too lean it will make it run hotter..
not to mention burn a valve...
other things a slipping torque converter or clutch will make it run
hotter..
hope some of these ideas help you ..
if you are running a 2 or 3 core radiator consider going to a 4 core.
eugene68
dvalentine
Charter Member
Also, Look at your hoses, upper and lower. If they feel too mushy the lower might be collapsing blocking the flow.
The other most obvious cause is the water pump. Take the tension off the belt and see if the pully water pump pully has any play. If there is any noticable play, replace the pump. Mine was overheating at parade speed, or drive through wait time with my old motor. I went through all the hoses, thermostat, installed a fan shroud. Even thought my water pump had NO play, I replaced it anyway. That did the trick...
Worst case ? check the oil for coolant, ( looks like bubbles on the oil dip stick), or the coolant for oil. That most likely indicates a blown head gasket. Don't drive it if you find oil and coolant co-habitating !!
DV
The other most obvious cause is the water pump. Take the tension off the belt and see if the pully water pump pully has any play. If there is any noticable play, replace the pump. Mine was overheating at parade speed, or drive through wait time with my old motor. I went through all the hoses, thermostat, installed a fan shroud. Even thought my water pump had NO play, I replaced it anyway. That did the trick...
Worst case ? check the oil for coolant, ( looks like bubbles on the oil dip stick), or the coolant for oil. That most likely indicates a blown head gasket. Don't drive it if you find oil and coolant co-habitating !!
DV
flushing the radiator didn't help. The water pump feels good but I don't have any pressure on the top hose. Also the truck dosn't have an overflow tank.The belt is not slipping. Still getting very hot. Any other ideas?
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Attachments:
https://talk.classicparts.com/images/attachments/Still hot