Overheating problem
Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1
From: NJ
Overheating problem
My 1990 corvette has been overheating, coolant just slowly climbs up and over past operating temperature, never let it get to the boiling point though, any suggestions? I’m not sure if it’s correlated but the oil temperature seems to go up incredibly slowly as well. My first step will be flushing the coolant as well as changing the thermostat, not sure if it’ll fix the problem, but we will see.
Last edited by Alexh4505; Sep 21, 2020 at 10:52 PM.
Le Mans Master
Joined: Jul 2004
Posts: 6,229
Likes: 698
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
My 1990 corvette has been overheating, coolant just slowly climbs up and over past operating temperature, never let it get to the boiling point though, any suggestions? I’m not sure if it’s correlated but the oil temperature seems to go up incredibly slowly as well. My first step will be flushing the coolant as well as changing the thermostat, not sure if it’ll fix the problem, but we will see.
Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1
From: NJ
It never stops, but by either coasting without accelerating or pulling off and letting it cool, I've never let it reach 260 degrees. Definitely could reach it and it has been incredibly close to before.
Racer
Joined: Aug 2020
Posts: 362
Likes: 81
From: Indianapolis
I’d start by making sure your fans are coming on — should hear them/get a drop in volts at about 215. Next, make sure there’s no junk between the radiator and the AC condenser. Is your overflow tank full, or are you losing coolant? I’d flush the system after checking on those things.
Hope that helps,
Ronn
Hope that helps,
Ronn
Last edited by Ronn38; Sep 22, 2020 at 08:27 AM.
Le Mans Master
Joined: Jul 2004
Posts: 6,229
Likes: 698
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Then you need to get your radiator out of the car for cleaning. That and a new thermostat will likely fix the problem.
It could look like this and it can't be cleaned thoroughly without removing
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Cooling is quite basic. Air flow and coolant flow. Stop one, or both, and the temps will rise.
Heed the suggestions for fan operation, and a clear path for air flow through the radiator..
A t-stat not opening fully will cause high temps.
Insufficient coolant with cause high temps.
A faulty water pump will cause high temps.
Include with the coolant flush remove/replace the knock sensor(s).
Check the coolant reservoir cap gasket for distortion. Replace, if necessary.
A head gasket breach allowing exhaust gases into the cooling system will cause a rapid rise in temp.
Cooling has been a popular subject since day-one. There are probably a thousand posts on cooling.
Spend some time researching old threads. It will be a tedious project, but you will learn how to use
the search feature for future concerns.
Good luck with your vette.
Heed the suggestions for fan operation, and a clear path for air flow through the radiator..
A t-stat not opening fully will cause high temps.
Insufficient coolant with cause high temps.
A faulty water pump will cause high temps.
Include with the coolant flush remove/replace the knock sensor(s).
Check the coolant reservoir cap gasket for distortion. Replace, if necessary.
A head gasket breach allowing exhaust gases into the cooling system will cause a rapid rise in temp.
Cooling has been a popular subject since day-one. There are probably a thousand posts on cooling.
Spend some time researching old threads. It will be a tedious project, but you will learn how to use
the search feature for future concerns.
Good luck with your vette.
Last edited by don hall; Sep 22, 2020 at 03:33 PM.
Pro
Joined: Aug 2020
Posts: 649
Likes: 126
From: Liliha Bakery stuffing my face with coco puffs!
Cooling is quite basic. Air flow and coolant flow. Stop one, or both, and the temps will rise.
Heed the suggestions for fan operation, and a clear path for air flow through the radiator..
A t-stat not opening fully will cause high temps.
Insufficient coolant with cause high temps.
A faulty water pump will cause high temps.
Include with the coolant flush remove/replace the knock sensor(s).
Check the coolant reservoir cap gasket for distortion. Replace, if necessary.
A head gasket breach allowing exhaust gases into the cooling system will cause a rapid rise in temp.
Cooling has been a popular subject since day-one. There are probably a thousand posts on cooling.
Spend some time researching old threads. It will be a tedious project, but you will learn how to use
the search feature for future concerns.
Good luck with your vette.
Heed the suggestions for fan operation, and a clear path for air flow through the radiator..
A t-stat not opening fully will cause high temps.
Insufficient coolant with cause high temps.
A faulty water pump will cause high temps.
Include with the coolant flush remove/replace the knock sensor(s).
Check the coolant reservoir cap gasket for distortion. Replace, if necessary.
A head gasket breach allowing exhaust gases into the cooling system will cause a rapid rise in temp.
Cooling has been a popular subject since day-one. There are probably a thousand posts on cooling.
Spend some time researching old threads. It will be a tedious project, but you will learn how to use
the search feature for future concerns.
Good luck with your vette.
Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1
From: NJ
Cooling is quite basic. Air flow and coolant flow. Stop one, or both, and the temps will rise.
Heed the suggestions for fan operation, and a clear path for air flow through the radiator..
A t-stat not opening fully will cause high temps.
Insufficient coolant with cause high temps.
A faulty water pump will cause high temps.
Include with the coolant flush remove/replace the knock sensor(s).
Check the coolant reservoir cap gasket for distortion. Replace, if necessary.
A head gasket breach allowing exhaust gases into the cooling system will cause a rapid rise in temp.
Cooling has been a popular subject since day-one. There are probably a thousand posts on cooling.
Spend some time researching old threads. It will be a tedious project, but you will learn how to use
the search feature for future concerns.
Good luck with your vette.
Heed the suggestions for fan operation, and a clear path for air flow through the radiator..
A t-stat not opening fully will cause high temps.
Insufficient coolant with cause high temps.
A faulty water pump will cause high temps.
Include with the coolant flush remove/replace the knock sensor(s).
Check the coolant reservoir cap gasket for distortion. Replace, if necessary.
A head gasket breach allowing exhaust gases into the cooling system will cause a rapid rise in temp.
Cooling has been a popular subject since day-one. There are probably a thousand posts on cooling.
Spend some time researching old threads. It will be a tedious project, but you will learn how to use
the search feature for future concerns.
Good luck with your vette.
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Thread Starter
Cruising
Joined: Sep 2020
Posts: 11
Likes: 1
From: NJ
I kept your advice in mind while I changed the coolant, which was a disgusting dark shade of green, as well as the old thermostat. I was able to peek in through the shrouds on each side and the radiator looked very clean, and I made sure the fans worked. Now the temp stays exactly where it should, 160~ at idle, 220~ when moving. Seems like the coolant wasn’t changed for quite some time. Thank you for your advice!