Hey guys. I am hoping you guys can help me. I took my 81 out for a quick spin today when i start see smoke and smelling coolant, so I hurried back home. I realized that there was a 6 inch round puddle under the car from before i took it out on the passenger side almost right under the resevoir. By the time i got it back home, the resevoir was empty and coolant was ALL OVER THE engine. What do you guys think it is? upper or lower hose? Or perhaps the actually resevoir? How can i tell/check? Also i think maybe some AC fluid had leaked out as well after the coolant? Is this normal with a coolant issue, or might I have 2 problems on hand? Please help! Thanks a milliion in advance.
Coolant leak HELP!
- Thread starter jforte
- Start date
minifridge1138
Well-known member
First, there is no AC fluid.
The Air Conditioner uses compressed freon gas to chill the air. If the system is leaking you won't find a puddle, you'll just notice that your ac doesn't get very cold and your compressor will engage/disengage more often until there is too little to trip the low pressure switch and then the clutch won't engage at all.
The fact that you have a coolant puddle on the left side means that you most likely have an overheating problem (C3's are notorious for overheating due to the size of the grill). When the fluid starts to get hot, it builds up pressure in the radiator. When the pressure gets high, the fluid is supposed to open a relief valve in the radiator cap and "spill" back into the reservoir. If it gets TOO hot it can overfill the reservoir and pour out of the top of the reservoir.
How often do you drive the car?
What is the outside air temperature?
What does your coolant temp gauge read?
How old is your thermostat?
How long has it been since you flushed the radiator?
How old is your radiator cap?
The Air Conditioner uses compressed freon gas to chill the air. If the system is leaking you won't find a puddle, you'll just notice that your ac doesn't get very cold and your compressor will engage/disengage more often until there is too little to trip the low pressure switch and then the clutch won't engage at all.
The fact that you have a coolant puddle on the left side means that you most likely have an overheating problem (C3's are notorious for overheating due to the size of the grill). When the fluid starts to get hot, it builds up pressure in the radiator. When the pressure gets high, the fluid is supposed to open a relief valve in the radiator cap and "spill" back into the reservoir. If it gets TOO hot it can overfill the reservoir and pour out of the top of the reservoir.
How often do you drive the car?
What is the outside air temperature?
What does your coolant temp gauge read?
How old is your thermostat?
How long has it been since you flushed the radiator?
How old is your radiator cap?
- Thread starter
- #3
Thanks for your response. I purchased the car 2 months ago. It has 16K original miles. It just recently got cold here in CT and is in the low 40's. I have no idea how old the thermostat and/or radiator cap are. They are obviously both cheap and easy to replace i can do that. I can flush out the coolant too, i am just hesitant to do that if there is a possible leak.....
minifridge1138
Well-known member
Congratulations on your new car.
Just be patient and you'll have it street worthy again.
I would clean all of the coolant off of the floor and out of the engine compartment.
If you have the tools or want to take it to a mechanic they can do a pressure test of the coolant system to check for leaks.
I don't have the correct tool and do as much work myself, so I would...
**** BE VERY CAREFUL. THE ENGINE WILL BE HOT AND IT IS VERY EASY TO BURN YOURSELF. NEVER OPEN A RADIATOR CAP OR TOUCH A COOLANT HOSE UNLESS THE ENGINE IS COLD ********
With a cold engine, I would fill the radiator and the reservoir to the full-cold line. Check to make sure all of the hose clamps are tight and that none of the hoses are dry-rotted or have obvious holes.
Check for puddles, drips, and leaks.
Then start it in the garage and let it idle.
Check for puddles, drips, and leaks.
Let it warm up until the thermostat opens (it could take a while if it is 40 outside).
Check for puddles, drips, and leaks.
The temperature should stay between 160-200 depending on what thermostat is in it (ideally, you want a 180 thermostat). If it goes way over that (such as 240+) then I would suspect you have a problem in your cooling system. It could go a little over because the car is not moving so there is no air flow across the radiator.
A basic guideline for engine temp is: engine temp = outside air temp + 110 (rough guideline, not a rule). So if it is 40 degrees, you should run around 150. That is colder than the thermostat, so you should run at the thermostat's rating.
If it stays around that at idle, and there are no leaks, then I would take it for a drive. See how the temperature changes at slow cruising and highway speeds. Stay close to home. Keep an eye on the gauge. Go home.
Check for puddles, drips, and leaks.
There are 3 things that can cause overheating:
1) lack of airflow across the radiator. Big problem with C3 because there is really no grill. Make sure you have the fan shroud (if using stock fan), lower air duct, and shroud-to-radiator seals.
2) lack of coolant circulation. Could be stuck thermostat, gunk built up along water jackets, plugged up radiator, water pump is bad (I've seen some where the aluminum impeller in the water pump broke loose from the shaft. Pump looked fine from the outside but didn't pump fluid).
3) lack of cooling capacity within the radiator. Some of the aftermarket radiators are too small and simply can not dissipate the amount of heat generated by these engines. Combined with (1) above and you have a big problem.
My 1982 had a 2 core brass radiator and would hit 240 degrees during a cool day. I replaced it with a DeWitt aluminum radiator ($$$$ but worth it IMHO) and I can drive across texas in July with the AC on and crack 200 degrees.
Luckily, these are cast iron blocks so it takes a lot to crack them (but it can be done). I probably would have melted an aluminum block before I solved my problems.
Good Luck and Welcome!!!
Just be patient and you'll have it street worthy again.
I would clean all of the coolant off of the floor and out of the engine compartment.
If you have the tools or want to take it to a mechanic they can do a pressure test of the coolant system to check for leaks.
I don't have the correct tool and do as much work myself, so I would...
**** BE VERY CAREFUL. THE ENGINE WILL BE HOT AND IT IS VERY EASY TO BURN YOURSELF. NEVER OPEN A RADIATOR CAP OR TOUCH A COOLANT HOSE UNLESS THE ENGINE IS COLD ********
With a cold engine, I would fill the radiator and the reservoir to the full-cold line. Check to make sure all of the hose clamps are tight and that none of the hoses are dry-rotted or have obvious holes.
Check for puddles, drips, and leaks.
Then start it in the garage and let it idle.
Check for puddles, drips, and leaks.
Let it warm up until the thermostat opens (it could take a while if it is 40 outside).
Check for puddles, drips, and leaks.
The temperature should stay between 160-200 depending on what thermostat is in it (ideally, you want a 180 thermostat). If it goes way over that (such as 240+) then I would suspect you have a problem in your cooling system. It could go a little over because the car is not moving so there is no air flow across the radiator.
A basic guideline for engine temp is: engine temp = outside air temp + 110 (rough guideline, not a rule). So if it is 40 degrees, you should run around 150. That is colder than the thermostat, so you should run at the thermostat's rating.
If it stays around that at idle, and there are no leaks, then I would take it for a drive. See how the temperature changes at slow cruising and highway speeds. Stay close to home. Keep an eye on the gauge. Go home.
Check for puddles, drips, and leaks.
There are 3 things that can cause overheating:
1) lack of airflow across the radiator. Big problem with C3 because there is really no grill. Make sure you have the fan shroud (if using stock fan), lower air duct, and shroud-to-radiator seals.
2) lack of coolant circulation. Could be stuck thermostat, gunk built up along water jackets, plugged up radiator, water pump is bad (I've seen some where the aluminum impeller in the water pump broke loose from the shaft. Pump looked fine from the outside but didn't pump fluid).
3) lack of cooling capacity within the radiator. Some of the aftermarket radiators are too small and simply can not dissipate the amount of heat generated by these engines. Combined with (1) above and you have a big problem.
My 1982 had a 2 core brass radiator and would hit 240 degrees during a cool day. I replaced it with a DeWitt aluminum radiator ($$$$ but worth it IMHO) and I can drive across texas in July with the AC on and crack 200 degrees.
Luckily, these are cast iron blocks so it takes a lot to crack them (but it can be done). I probably would have melted an aluminum block before I solved my problems.
Good Luck and Welcome!!!
wishuwerehere82
Well-known member
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The hose between the radiator cap and the reservoir can crack, letting the reservoir drain. Or the reservoir can crack, causing a complete loss of coolant in the reservoir.
But what happens a lot of times is that the thermostatic valve on the radiator cap gets clogged. The valve is open when the engine is cool, and allows the coolant in the recovery tank to refill the block. Then the valve closes as the engine warms up and retains pressure in the radiator. That's why you have the variation in volume between cold and hot in the reservoir.
If the valve sticks open the radiator will boil out through the hose to the recovery tank. And as soon as you shut the engine down, the entire contents of the tank will suck back into the radiator within seconds.
My advice is to refill the radiator, then warm it up and observe what is going on with the engine running until you can see where the coolant is leaking from.
But what happens a lot of times is that the thermostatic valve on the radiator cap gets clogged. The valve is open when the engine is cool, and allows the coolant in the recovery tank to refill the block. Then the valve closes as the engine warms up and retains pressure in the radiator. That's why you have the variation in volume between cold and hot in the reservoir.
If the valve sticks open the radiator will boil out through the hose to the recovery tank. And as soon as you shut the engine down, the entire contents of the tank will suck back into the radiator within seconds.
My advice is to refill the radiator, then warm it up and observe what is going on with the engine running until you can see where the coolant is leaking from.
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- #6
Crimson Thunder
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Because you just recently purchased the car and with so low miles,I would drain the coolant and check all the hoses and clamps.Its amazing how a little bit of scale on the radiator neck or the water pump outlet can cause coolant to leak past the clamp.Your car is probably due for a coolant change anyway.
bradfordsvettes
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crawl under and check the weep hole at the bottom of the water pump the seal may be starting to go and it would run down the hose on the r/s front of the car it would be worth a look or get a pressure tester and add 15psi and check for leaks Steve
- Thread starter
- #9
LVMYVT76
Well-known member
I bet the water pump seal is leaking, or a freeze plug has rusted thru.
- Thread starter
- #11
Well i just put some water in the resevoir, and nothing leaked, i started the car up, pull out of the garage and let it warm up, it just kept getting hotter, but no leak. I am thinking the radiator cap blew open to release the pressure when it got hot when i drove, I am going to replace the thermostat and the radiator cap, i just hope it is not the water pump...I don't think any of the hoses are leaking, as i filled the resevoir and nothing leaked after i pulled it out and let it sit running. I shut it off before it reached the red. THe radiator was smoking when i turned it off.
Vettehead Mikey
Well-known member
Are you saying that you just ran the car now and the temp went above normal? Did you remove the radiator cap and verify that the rad is full before filling the overflow tank?
minifridge1138
Well-known member
you definitely have a cooling problem. A big one.
I would start with the cheap and easy: thermostat and radiator cap.
Who know show old they are.
Since it boiled over just from idling I would say you have a circulation problem.
I would start with the cheap and easy: thermostat and radiator cap.
Who know show old they are.
Since it boiled over just from idling I would say you have a circulation problem.
- Thread starter
- #14
I just spent a few hours with the car. I replaced the thermostat, and radiator cap. I drained all the fluid out of the car. Filled it up with the radiator cleaner/water to the TOP, replaced radiator cap, made sure the resevoir was full, and started the car. Almost immediately water was POURING out underneath like mad. the inside of the radiator did have some white build up which i am sure was not helping anything, but the holes were there, so water was getting through. I THINK it was the waterpump, but not sure. I have my mechanic coming tommorrow to pick it up.....it is beginning to get past my level of ability. I thank you all for your help, and i do think it is a circulation problem as well, i really do think it's the waterpump, we will see! I will post results when i know, thanks again for all your help guys!
minifridge1138
Well-known member
You say that coolant spilled out, but spilled out of what? Radiator, reservoir, etc?
If there was white build up in the radiator, then you can bet it has built up inside the engine block as well. It would also explain why the radiator is unable to keep the block cool.
Good luck with the mechanic. It is very hard to diagnose problems over the internet, so all we are doing is guessing.
Luckily this forum has some very, very good guessers.
If there was white build up in the radiator, then you can bet it has built up inside the engine block as well. It would also explain why the radiator is unable to keep the block cool.
Good luck with the mechanic. It is very hard to diagnose problems over the internet, so all we are doing is guessing.
Luckily this forum has some very, very good guessers.
- Thread starter
- #16
You say that coolant spilled out, but spilled out of what? Radiator, reservoir, etc?
If there was white build up in the radiator, then you can bet it has built up inside the engine block as well. It would also explain why the radiator is unable to keep the block cool.
Good luck with the mechanic. It is very hard to diagnose problems over the internet, so all we are doing is guessing.
Luckily this forum has some very, very good guessers.
Yes, thanks again and thanks everyone. My mechanic is actually a good friend, who is a top top mechanic, builds engines, and has worked on countless Vette's of all generations. He will bang it out quick. I was just trying to do it myself because i get satisfaction out of "doing it yourself". Thanks.
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