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84 Corvette overheating***Please help***
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
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84 Corvette overheating***Please help***
Hi everyone, hoping someone might be able to help me out here... So, my 84 which I recently got has an overheating issue. I believe I had something to do with it. The car was originally wired so the fan was always on. So I screwed with the wires and while the car was on and the fan was running, one of the wires was rubbing on a belt and I believe it may have short circuited something to do with the cooling system? I say this because it was working fine before that. I checked the fuses on the side of the dash and nothing seems to be bad. The car really doesn't overheat when just parked, but when driving, the temp goes up very quickly and today it got over 250. The fluid is full and I don't see any leaks. Please help if possible...just registered it and can't even driver her. THANKS!!
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
You should check (in order of likelihood)
*Debris between the radiator and AC condenser
*Contaminated cooling system (needs flushing)
*Stuck thermostat
*Bad water pump.
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
Likes: 0
Thanks
Thanks for the quick reply. Also if this helps at all.. just took it out for a quick ride around the block and the temp continued to rise, but when stopped at stop signs the temp kinda stopped rising until I took back off. Thanks again... and I will make the attempt to check those on the list, although I am not too car savvy.
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
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the book said to check the pump squeeze the upper radiator hose and if there was no change in pressure then it was bad...well I think i squeezed the right hose and felt no change...I assume this is my problem if I did in fact squeeze the right one?
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
What book? That isn't a very good test, IMO.
The driver's side hose is the left hose, and it's also the Upper hose. The "right hose" would be on the passenger's side, down low...the lower hose.
It's very unlikely that the pump is bad. The only way for a pump tp go bad, that would cause over heating would be if the impeller came disconnected from the shaft, or it rotted away. Both very unlikely, but possible. That's why it's the lowest item on my list. usually, long, LONG before the ipump impeller fails, the bearing or seal fails, and it spews coolant all over the ground.
When the temp is on the rise, does the heater blow heat?
The driver's side hose is the left hose, and it's also the Upper hose. The "right hose" would be on the passenger's side, down low...the lower hose.
It's very unlikely that the pump is bad. The only way for a pump tp go bad, that would cause over heating would be if the impeller came disconnected from the shaft, or it rotted away. Both very unlikely, but possible. That's why it's the lowest item on my list. usually, long, LONG before the ipump impeller fails, the bearing or seal fails, and it spews coolant all over the ground.
When the temp is on the rise, does the heater blow heat?
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
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Well that is good to hear because I was checking it out and really didn't want to deal with replacing the pump. I will check if it blows heat. Are you saying to get it up to temp and while the temp is rising put heat on and see if it blows? Or see if heat goes through it without turning it on? Sorry I'm so dumb with this stuff. Thanks so much for taking the time to help me.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Yes, get it up to temp, turn the heater on. If your water pump isn't working, (or if you're simply low on coolant) the heater will blow ambient temp air...not HOT air like it should. So if you're heater blows HOT air when set to "heat" and warmed up, then that is a good indicator that your pump is working and you have enough coolant.
I'm only advocating that check, b/c it's so quick and easy. If your car were mine, I'd already have the fan shroud off, to clean the debris from between the Radiator and ac condenser and I'd already have all the coolant drained, flushed, and refilled...then I'd be assessing cooling system performance from there.
I'm only advocating that check, b/c it's so quick and easy. If your car were mine, I'd already have the fan shroud off, to clean the debris from between the Radiator and ac condenser and I'd already have all the coolant drained, flushed, and refilled...then I'd be assessing cooling system performance from there.
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Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
When the car is cold remove the radidtor car then turn it on and just let it run. When the thermostat opens youll know it the water will start moving around. See if you hear the fans kick on. Sounds like somoene by passed the relay/switch that oughta be fixed, un bubba ing your car will bring more enjoyment. Is the plug with wires to your AC compressor fully pushed in?
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
His car is overheating at speed/on the open road. Fans are out of the picture during that mode of operation.
Your pump is working, your system is full (enough) of coolant.
What this leaves is (in order of likelihood)
*Debris between the radiator and AC condenser
*Contaminated cooling system (needs flushing)
*Stuck thermostat
What this leaves is (in order of likelihood)
*Debris between the radiator and AC condenser
*Contaminated cooling system (needs flushing)
*Stuck thermostat
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
Likes: 0
When the car is cold remove the radidtor car then turn it on and just let it run. When the thermostat opens youll know it the water will start moving around. See if you hear the fans kick on. Sounds like somoene by passed the relay/switch that oughta be fixed, un bubba ing your car will bring more enjoyment. Is the plug with wires to your AC compressor fully pushed in?
Also, so you say to take cap off and let it run and I will hear fans.. I assume you mean internal fans? like not the big one? sorry.... this is all foreign to me, wish I knew more.
Thanks so much
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
Likes: 0
His car is overheating at speed/on the open road. Fans are out of the picture during that mode of operation.
Your pump is working, your system is full (enough) of coolant.
What this leaves is (in order of likelihood)
*Debris between the radiator and AC condenser
*Contaminated cooling system (needs flushing)
*Stuck thermostat
Your pump is working, your system is full (enough) of coolant.
What this leaves is (in order of likelihood)
*Debris between the radiator and AC condenser
*Contaminated cooling system (needs flushing)
*Stuck thermostat
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
...The number one, most likely and most common cause of hot running in a C4 (why it was at the TOP of my list for you). Should be a regular maintenance item on all C4's.
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
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Ahh yes, thought that a flush would cover that, sorry. I assume that is nothing I can do either? So a shop for both of those would be my best action? Is it tough to do myself if I use the repair manual and good ol' google?
Burning Brakes
Joined: Apr 2016
Posts: 781
Likes: 73
I would be looking at a stuck thermostat first.
Squeezing the upper radiator hose is an old timer (like me) test to quickly let you know if water is circulating through the system once the engine gets up to temperature.
You should "feel" water being pumped through the upper hose when squeezed, after the car reaches the temperature of whatever degree thermostat you are running. The hose should also be warm/hot to the touch.
If you do not "feel" water pumping it could be the pump or the thermostat. The thermostat is pretty easy to test. Take it out and drop it in a pot of boiling water. If it opens the thermostat is good, if it stays closed the thermostat is bad and should be replaced.
The typical failure on a water pump is the front bearing. There should be a weep hole in the front of the pump. If you see/smell coolant in that area then you are probably needing to replace the pump.
The non-typical failure on a water pump is an impeller failing. I cannot recall the last time I saw one of those fail on a small block Chevy.
Squeezing the upper radiator hose is an old timer (like me) test to quickly let you know if water is circulating through the system once the engine gets up to temperature.
You should "feel" water being pumped through the upper hose when squeezed, after the car reaches the temperature of whatever degree thermostat you are running. The hose should also be warm/hot to the touch.
If you do not "feel" water pumping it could be the pump or the thermostat. The thermostat is pretty easy to test. Take it out and drop it in a pot of boiling water. If it opens the thermostat is good, if it stays closed the thermostat is bad and should be replaced.
The typical failure on a water pump is the front bearing. There should be a weep hole in the front of the pump. If you see/smell coolant in that area then you are probably needing to replace the pump.
The non-typical failure on a water pump is an impeller failing. I cannot recall the last time I saw one of those fail on a small block Chevy.
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
Likes: 0
I would be looking at a stuck thermostat first.
Squeezing the upper radiator hose is an old timer (like me) test to quickly let you know if water is circulating through the system once the engine gets up to temperature.
You should "feel" water being pumped through the upper hose when squeezed, after the car reaches the temperature of whatever degree thermostat you are running. The hose should also be warm/hot to the touch.
If you do not "feel" water pumping it could be the pump or the thermostat. The thermostat is pretty easy to test. Take it out and drop it in a pot of boiling water. If it opens the thermostat is good, if it stays closed the thermostat is bad and should be replaced.
The typical failure on a water pump is the front bearing. There should be a weep hole in the front of the pump. If you see/smell coolant in that area then you are probably needing to replace the pump.
The non-typical failure on a water pump is an impeller failing. I cannot recall the last time I saw one of those fail on a small block Chevy.
Squeezing the upper radiator hose is an old timer (like me) test to quickly let you know if water is circulating through the system once the engine gets up to temperature.
You should "feel" water being pumped through the upper hose when squeezed, after the car reaches the temperature of whatever degree thermostat you are running. The hose should also be warm/hot to the touch.
If you do not "feel" water pumping it could be the pump or the thermostat. The thermostat is pretty easy to test. Take it out and drop it in a pot of boiling water. If it opens the thermostat is good, if it stays closed the thermostat is bad and should be replaced.
The typical failure on a water pump is the front bearing. There should be a weep hole in the front of the pump. If you see/smell coolant in that area then you are probably needing to replace the pump.
The non-typical failure on a water pump is an impeller failing. I cannot recall the last time I saw one of those fail on a small block Chevy.
Thanks for the help, I did attempt this earlier but I didn't feel anything flowing. although, I am not sure that I checked the right hose.... which is the correct hose (what are the two connections of the correct hose? All of the hoses which I did squeeze were very hot but didn't feel like anything was flowing.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Here look at this, HERE. That is my car, a '92. It's different than your '84 so details will differ, but functionally and philosophically, it's the same as your car. Look at the pic of the radiator, after I removed the shroud...this pic:
See all that crap covering the front of the radiator? That is going to limit air flow....and that "crap" is on MY car -a car that gets regular maintenance/cleaning of things like that. You just bought your car. It's previous care is unknown, therefore, things like cleaning this area out, and coolant flush are basic maintenance items that should be done anyway, IMO, with a new-to-you car.
Anyone can do this maintenance stuff themselves if they try...you bought an old Corvette. I'd start getting used to working on it myself if I were you...or you better have an open line of credit w/your mechanic!
.
Last edited by Tom400CFI; Apr 30, 2016 at 06:14 PM.
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
Likes: 0
You can do all of it. None of it is hard. You CAN Google...but most answers are already on here if you search, using the "Advanced search" feature.
Here look at this, HERE. That is my car, a '92. It's different than your '84 so details will differ, but functionally and philosophically, it's the same as your car. Look at the pic of the radiator, after I removed the shroud...this pic:
See all that crap covering the front of the radiator? That is going to limit air flow....and that "crap" is on MY car -a car that gets regular maintenance/cleaning of things like that. You just bought your car. It's previous care is unknown, therefore, things like cleaning this area out, and coolant flush are basic maintenance items that should be done anyway, IMO, with a new-to-you car.
Anyone can do this maintenance stuff themselves if they try...you bought an old Corvette. I'd start getting used to working on it myself if I were you...or you better have an open line of credit w/your mechanic!
.
Here look at this, HERE. That is my car, a '92. It's different than your '84 so details will differ, but functionally and philosophically, it's the same as your car. Look at the pic of the radiator, after I removed the shroud...this pic:
See all that crap covering the front of the radiator? That is going to limit air flow....and that "crap" is on MY car -a car that gets regular maintenance/cleaning of things like that. You just bought your car. It's previous care is unknown, therefore, things like cleaning this area out, and coolant flush are basic maintenance items that should be done anyway, IMO, with a new-to-you car.
Anyone can do this maintenance stuff themselves if they try...you bought an old Corvette. I'd start getting used to working on it myself if I were you...or you better have an open line of credit w/your mechanic!
.
That is awesome thank you! I will probably make the attempt tomorrow maybe. Hopefully I can manage.
Thread Starter
Heel & Toe
Joined: Apr 2016
Posts: 24
Likes: 0
You can do all of it. None of it is hard. You CAN Google...but most answers are already on here if you search, using the "Advanced search" feature.
Here look at this, HERE. That is my car, a '92. It's different than your '84 so details will differ, but functionally and philosophically, it's the same as your car. Look at the pic of the radiator, after I removed the shroud...this pic:
See all that crap covering the front of the radiator? That is going to limit air flow....and that "crap" is on MY car -a car that gets regular maintenance/cleaning of things like that. You just bought your car. It's previous care is unknown, therefore, things like cleaning this area out, and coolant flush are basic maintenance items that should be done anyway, IMO, with a new-to-you car.
Anyone can do this maintenance stuff themselves if they try...you bought an old Corvette. I'd start getting used to working on it myself if I were you...or you better have an open line of credit w/your mechanic!
.
Here look at this, HERE. That is my car, a '92. It's different than your '84 so details will differ, but functionally and philosophically, it's the same as your car. Look at the pic of the radiator, after I removed the shroud...this pic:
See all that crap covering the front of the radiator? That is going to limit air flow....and that "crap" is on MY car -a car that gets regular maintenance/cleaning of things like that. You just bought your car. It's previous care is unknown, therefore, things like cleaning this area out, and coolant flush are basic maintenance items that should be done anyway, IMO, with a new-to-you car.
Anyone can do this maintenance stuff themselves if they try...you bought an old Corvette. I'd start getting used to working on it myself if I were you...or you better have an open line of credit w/your mechanic!
.
I don't know if this makes a difference, but I just looked at the front of the radiator from under the car and I could see the while thing and did not see any debris at all... it did look slightly bent in some areas and kinda old maybe... but I guess either way I can do that and flush it all and check the thermostat while in the process of flushing. Thanks sorry to keep bothering.