What could possibly be wrong with this cooling system???????
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
This is a slick tool my friend let me borrow and I've since bought my own:
http://www.denlorstools.com/home/dt1...fill_adap.html
When the funnel is filled, the liquid level is higher than any point on the motor, so all the air is pushed out. Having a small relief hole in the T-stat makes it quicker.
http://www.denlorstools.com/home/dt1...fill_adap.html
When the funnel is filled, the liquid level is higher than any point on the motor, so all the air is pushed out. Having a small relief hole in the T-stat makes it quicker.
First check the coolant level, if the coolant is low enough this alone could be the problem. The coolant could be low enough to affect the heater however, not low enough to cause the engine temperature to rise above the normal range. Pressure test the system to make sure there is no leak, even a drip can cause enough coolant loss to affect the heater performance, due to air pockets being introduced.
If the heater does eventually work after the vehicle has been ran for an extended period of time, the thermostat could be stuck in the open position. This allows the coolant to flow continuously, preventing the engine from reaching operating temperature quickly. As you know a stuck closed thermostat presents a much more urgent problem than heater performance.
Particularly if the cooling system on the car you are working on looks like it has been neglected, there is a chance there could be a restriction in the radiator or the heater core. On rare occasion, the fins of the impeller on the water pump could be rusted to a point that it is no longer pumping the coolant. If the impeller is plastic and not subject to corrosion, it is possible for it to stress crack an come loose from the shaft.
If equipped, verify heater control valve operation and control cable adjustment to make sure the valve is being opened completely. Use an infrared thermometer or feel the heater hose temperatures at the heater core. If the hoses are both warm, the coolant is flowing through the heater core. The temperature blend cable or actuator should be checked for proper operation, the blend door may not be moving fully or at all.
If there is a major difference in the temperature of the two hoses, there is a possibility there is air trapped in the heater core or at some portion of the cooling system, preventing the flow through the heater core. Some models have one or more bleeder valves to purge the air out of the cooling system, refer to the service manual for the specific vehicle. The use of a coolant fill funnel like the Lisle LIS22150 works wonders in purging the air from cooling systems. The Lisle coolant fill funnel allows coolant to fill the void as the air slowly works its way to the surface. The air is removed when the heater is blowing hot air and there are no more air bubbles surfacing in the coolant fill funnel.
If the heater does eventually work after the vehicle has been ran for an extended period of time, the thermostat could be stuck in the open position. This allows the coolant to flow continuously, preventing the engine from reaching operating temperature quickly. As you know a stuck closed thermostat presents a much more urgent problem than heater performance.
Particularly if the cooling system on the car you are working on looks like it has been neglected, there is a chance there could be a restriction in the radiator or the heater core. On rare occasion, the fins of the impeller on the water pump could be rusted to a point that it is no longer pumping the coolant. If the impeller is plastic and not subject to corrosion, it is possible for it to stress crack an come loose from the shaft.
If equipped, verify heater control valve operation and control cable adjustment to make sure the valve is being opened completely. Use an infrared thermometer or feel the heater hose temperatures at the heater core. If the hoses are both warm, the coolant is flowing through the heater core. The temperature blend cable or actuator should be checked for proper operation, the blend door may not be moving fully or at all.
If there is a major difference in the temperature of the two hoses, there is a possibility there is air trapped in the heater core or at some portion of the cooling system, preventing the flow through the heater core. Some models have one or more bleeder valves to purge the air out of the cooling system, refer to the service manual for the specific vehicle. The use of a coolant fill funnel like the Lisle LIS22150 works wonders in purging the air from cooling systems. The Lisle coolant fill funnel allows coolant to fill the void as the air slowly works its way to the surface. The air is removed when the heater is blowing hot air and there are no more air bubbles surfacing in the coolant fill funnel.
Instructor
Joined: Feb 2006
Posts: 112
Likes: 0
From: Vandenberg AFB California
I have an '88 that I had problems with earlier last year so I have a bit of experience with the cooling system. Chances are, it has nothing to do with your t-stat. L89 engines need to be burped when you mess with the coolent level.
Take off the coolant cap and start the engine. Keep the engine at around 2000 rpm (if you don't, you will notice that the coolant just flows out onto the ground) until it gets up to temp and the t-stat opens. Once it opens, the coolant level should drop. Quickly fill the radiator and then replace the cap. This should help, but you may have to do it a couple times.
If this doesn't help, check the sensor, and then the heads for a blown head gasket. If you still think it has something to do with the t-stat, just take it out and run it. See if anything changes or gets better.
Here is what I got off the forum when I was working this problem.
This page is in response to the numerous threads on temperature operating ranges and overheating complaints that comes up EVERY year on the forum starting in May. Since the Mods won't give us a sticky on it, I decided to write this up to save time writing it in each post.
Normal operating ranges,
Oil-anywhere between 210-230
Coolant-should settle at about 15-20F below the oil temperature
LT1 cars will run just a bit warmer than L98s, but the same ranges apply.
Main fan on/off:
Varies just a bit in exact temperature over the years, but it should come on anywhere between 225-228F (coolant), I say that because the in-car gauge is rarely so accurate for you to say its coming on exactly when the manual says it should.
The main fan will also cycle with the A/C running.
Aux fan (if you have it)-in front of your radiator and condenser, and it should come on just above your main fan temperature, say 228F, though in 85-86 it came on at 238F.
Stock Thermostats-
L98-195F (coolant)
LT1-180F (coolant)
Once the engine starts, your car will proceed upwards to the thermostat opening temperature, at which point it should hold steady as the stat cycles open and closed. At that time, the oil temperature will catch up with the coolant and usually passes it. This drags the coolant temp up towards the fan setting. Generally it'll settle at about 15-20F difference between the two.
Danger zone-if you have aluminum heads, do NOT allow the coolant to reach 250-260+, or you're risking a head gasket. That applies to both engines. A dino oil engine can handle oil temps ~250 for short durations, but above this the oil breaks down and you need to change it sooner than usual. Synthetics can withstand ~300F.
Things to do if you suspect the engine is overheating:
1.Check to see if the thermostat is indeed working. Car temperature should stabilize momentarily at the thermostat opening temperature. If it doesn’t, replace it.
2. Check to see if the fans are working. Let the car idle up to fan temperature and make sure they come on when they should. Try running the A/C to see the fan itself actually works at all; it should come on within a few minutes of running. Main fan relay is on the radiator shroud starting in '88, and earlier years have it just below the Master Cylinder on the wheel-well.
3. Check to make sure the WP is not weeping. There are weepholes in the WP that will leak when it’s bad. It’s hard to diagnose otherwise.
4. Remove air bubbles in the system, and check for pressure leaks. Old caps lose pressure and should be replaced every 2-3 years when you should flush your system. Also check for small leaks in the hose between radiator and overflow/surge tank and make sure all hoses are tightly clamped. Some leaks don’t happen until the engine is hot, you must be sure.
To burp the motor-for the L98 let the engine warm up with the rad. cap off, until the thermostat is open fully. While you are doing this, hold the engine at 2000rpm or the coolant will just bubble out. You can do it by yourself, but its best to have another person inside the car. Once the stat is open and the throttle is pressed, the coolant level will drop....fill it up and replace the cap. It may take 2 tries to get all of the air out. LT1 systems use a bleed screw next to the TB to allow air to escape.
5. Clean the space between radiator and condenser. The C4 is a vacuum cleaner and sucks things up through the nose, because the intake actually breathes in air after its passed through the radiator and condenser (not through the little air gaps in the hood or shroud). Debris passes above the condenser and settles in the space between it and the radiator. Once this is clogged the temps will end up about 10-15F higher. Dirt and grime will also cling to the fins in the radiator, and must be removed.
See the Techtip on doing this, you must remove the shroud (not as hard as it looks) to suck the debris out with a shop-vac. You should also remove the radiator and use a screwdriver to clean out the fins and straighten each one before putting it back in.
6. Flush the system-old coolant becomes acidic and eats away at rubber internals and the radiator itself, causing leaks to form. You should flush the system once every 2-3 years and replace with 50/50 coolant/distilled water mixture. You MUST use distilled water, regular tap has some of those acidic/ionic impurities aforementioned.
Does the car still overheat?:
If you see any plumes of white smoke in normal operation, once the car is hot (ignore any light wisps of smoke on startup, it may just be condensation in the exhaust, especially when it gets cold at night), then you have a head gasket failure. If it doesn’t do that and still continues to rise, then there’s either a pressure leak in the system that you haven’t found or it could still be a head gasket. It doesn’t have to look like a shuttle launch, but usually it does.
If the car is just running too hot for your tastes the only permanent fixes are a combination of the following,
1. Reset the fan temperature in the ECM, either from a chip or laptop tune for PCM modules. 195-210 should be fine.
2. Change the thermostat to a lower temperature; this applies more to L98s than LT1s in my opinion. I use a 160, and there’s another discussion of that whole debate on another page here.
3. Add a larger radiator. DeWitts, Griffin, BeCool, Davis, etc. These will not help idle temperatures so much, but once you get moving the temps drop fast. I now see a 30F difference between oil and coolant with the DeWitts on the highway, even on hot days it keeps the coolant low (mine was 180F in 100F outside heat at 70mph on the highway).
4. Better water pump-Stewart, FlowKooler, etc. These affect idle temperature rises more than anything else, since they pull coolant in and push it out faster than the stock pump at idle. The car will still proceed upwards in temperature t idle, but a bit slower.
I have done all 4 in that order to my car, and the first 2 fixed the problem.
Take off the coolant cap and start the engine. Keep the engine at around 2000 rpm (if you don't, you will notice that the coolant just flows out onto the ground) until it gets up to temp and the t-stat opens. Once it opens, the coolant level should drop. Quickly fill the radiator and then replace the cap. This should help, but you may have to do it a couple times.
If this doesn't help, check the sensor, and then the heads for a blown head gasket. If you still think it has something to do with the t-stat, just take it out and run it. See if anything changes or gets better.
Here is what I got off the forum when I was working this problem.
This page is in response to the numerous threads on temperature operating ranges and overheating complaints that comes up EVERY year on the forum starting in May. Since the Mods won't give us a sticky on it, I decided to write this up to save time writing it in each post.
Normal operating ranges,
Oil-anywhere between 210-230
Coolant-should settle at about 15-20F below the oil temperature
LT1 cars will run just a bit warmer than L98s, but the same ranges apply.
Main fan on/off:
Varies just a bit in exact temperature over the years, but it should come on anywhere between 225-228F (coolant), I say that because the in-car gauge is rarely so accurate for you to say its coming on exactly when the manual says it should.
The main fan will also cycle with the A/C running.
Aux fan (if you have it)-in front of your radiator and condenser, and it should come on just above your main fan temperature, say 228F, though in 85-86 it came on at 238F.
Stock Thermostats-
L98-195F (coolant)
LT1-180F (coolant)
Once the engine starts, your car will proceed upwards to the thermostat opening temperature, at which point it should hold steady as the stat cycles open and closed. At that time, the oil temperature will catch up with the coolant and usually passes it. This drags the coolant temp up towards the fan setting. Generally it'll settle at about 15-20F difference between the two.
Danger zone-if you have aluminum heads, do NOT allow the coolant to reach 250-260+, or you're risking a head gasket. That applies to both engines. A dino oil engine can handle oil temps ~250 for short durations, but above this the oil breaks down and you need to change it sooner than usual. Synthetics can withstand ~300F.
Things to do if you suspect the engine is overheating:
1.Check to see if the thermostat is indeed working. Car temperature should stabilize momentarily at the thermostat opening temperature. If it doesn’t, replace it.
2. Check to see if the fans are working. Let the car idle up to fan temperature and make sure they come on when they should. Try running the A/C to see the fan itself actually works at all; it should come on within a few minutes of running. Main fan relay is on the radiator shroud starting in '88, and earlier years have it just below the Master Cylinder on the wheel-well.
3. Check to make sure the WP is not weeping. There are weepholes in the WP that will leak when it’s bad. It’s hard to diagnose otherwise.
4. Remove air bubbles in the system, and check for pressure leaks. Old caps lose pressure and should be replaced every 2-3 years when you should flush your system. Also check for small leaks in the hose between radiator and overflow/surge tank and make sure all hoses are tightly clamped. Some leaks don’t happen until the engine is hot, you must be sure.
To burp the motor-for the L98 let the engine warm up with the rad. cap off, until the thermostat is open fully. While you are doing this, hold the engine at 2000rpm or the coolant will just bubble out. You can do it by yourself, but its best to have another person inside the car. Once the stat is open and the throttle is pressed, the coolant level will drop....fill it up and replace the cap. It may take 2 tries to get all of the air out. LT1 systems use a bleed screw next to the TB to allow air to escape.
5. Clean the space between radiator and condenser. The C4 is a vacuum cleaner and sucks things up through the nose, because the intake actually breathes in air after its passed through the radiator and condenser (not through the little air gaps in the hood or shroud). Debris passes above the condenser and settles in the space between it and the radiator. Once this is clogged the temps will end up about 10-15F higher. Dirt and grime will also cling to the fins in the radiator, and must be removed.
See the Techtip on doing this, you must remove the shroud (not as hard as it looks) to suck the debris out with a shop-vac. You should also remove the radiator and use a screwdriver to clean out the fins and straighten each one before putting it back in.
6. Flush the system-old coolant becomes acidic and eats away at rubber internals and the radiator itself, causing leaks to form. You should flush the system once every 2-3 years and replace with 50/50 coolant/distilled water mixture. You MUST use distilled water, regular tap has some of those acidic/ionic impurities aforementioned.
Does the car still overheat?:
If you see any plumes of white smoke in normal operation, once the car is hot (ignore any light wisps of smoke on startup, it may just be condensation in the exhaust, especially when it gets cold at night), then you have a head gasket failure. If it doesn’t do that and still continues to rise, then there’s either a pressure leak in the system that you haven’t found or it could still be a head gasket. It doesn’t have to look like a shuttle launch, but usually it does.
If the car is just running too hot for your tastes the only permanent fixes are a combination of the following,
1. Reset the fan temperature in the ECM, either from a chip or laptop tune for PCM modules. 195-210 should be fine.
2. Change the thermostat to a lower temperature; this applies more to L98s than LT1s in my opinion. I use a 160, and there’s another discussion of that whole debate on another page here.
3. Add a larger radiator. DeWitts, Griffin, BeCool, Davis, etc. These will not help idle temperatures so much, but once you get moving the temps drop fast. I now see a 30F difference between oil and coolant with the DeWitts on the highway, even on hot days it keeps the coolant low (mine was 180F in 100F outside heat at 70mph on the highway).
4. Better water pump-Stewart, FlowKooler, etc. These affect idle temperature rises more than anything else, since they pull coolant in and push it out faster than the stock pump at idle. The car will still proceed upwards in temperature t idle, but a bit slower.
I have done all 4 in that order to my car, and the first 2 fixed the problem.
Thread Starter
Drifting
Joined: Oct 2005
Posts: 1,257
Likes: 4
From: North Carolina
Skrud13,
That should ABSOLUTELY be sticky'd! It was extremely informative, and very helpful.
UPDATE: I added the new 180*F coolant fan switch today for the aux fan. This should hold me over till I can get the primary fan tuned to come on at 180*F. I also FINALLY found a leak... dripping from the upper radiator hose. The antifreeze has been collecting in the radiator support, then it dries up which is why I probably didn't originally see it. So I cut the hose and tightened the clamp, and it no longer seems to be leaking. I also lifted the front end up really high and bled the system at 2K RPMss. Ill let you guys know how it works out.
Lastly,... how can I program the primary fan to come on soon? Do I have the get the ECU tuned or can I somehow do it myself. If I need to buy a cable or something... ?????????????????
Anyway,
Thanks again for the help,
DG
That should ABSOLUTELY be sticky'd! It was extremely informative, and very helpful.
UPDATE: I added the new 180*F coolant fan switch today for the aux fan. This should hold me over till I can get the primary fan tuned to come on at 180*F. I also FINALLY found a leak... dripping from the upper radiator hose. The antifreeze has been collecting in the radiator support, then it dries up which is why I probably didn't originally see it. So I cut the hose and tightened the clamp, and it no longer seems to be leaking. I also lifted the front end up really high and bled the system at 2K RPMss. Ill let you guys know how it works out.
Lastly,... how can I program the primary fan to come on soon? Do I have the get the ECU tuned or can I somehow do it myself. If I need to buy a cable or something... ?????????????????
Anyway,
Thanks again for the help,
DG
Heel & Toe
Joined: Dec 2009
Posts: 18
Likes: 0
Hello,
I've never seen this before...maybe someone has!
I have replaced the thermostat in my 1995 coupe with an LT1, 4 times now in the last 6 months. They all have stuck in the closed position casing the obvious overheating. Each time I replaced one, I followed the "burping" proceedures and intitially all was well. If I let the car sit for a week or two, sure enough, the thermostat will stick and excessive tempuratures happen within 5 to 10 minutes of starting the car. I have tried different brands, I even spent $38 for a GM brand and it stuck closed as well. Recently, I had the transmission replaced by a qualified garage who I trust. The car had been unstarted for about 3 weeks while the transmission was built and shipped to this garage. On the test drive for the transmission, the thermostat stuck shut and a proper test was not conducted. The tech called me and told me what had happened and recommended that the thermostat be replaced. I told them to go ahead, maybe they know a better way to purge the cooling system. I picked the car up and drove it home, checked out fine. The next day I started it up and the new (4th) thermostat is stuck shut. I mean the temp gauge is almost pegged and the radiator is stone cold, the heater is blowing cold air.....can anyone offer some advice?
Please help! Thanks!
I've never seen this before...maybe someone has!
I have replaced the thermostat in my 1995 coupe with an LT1, 4 times now in the last 6 months. They all have stuck in the closed position casing the obvious overheating. Each time I replaced one, I followed the "burping" proceedures and intitially all was well. If I let the car sit for a week or two, sure enough, the thermostat will stick and excessive tempuratures happen within 5 to 10 minutes of starting the car. I have tried different brands, I even spent $38 for a GM brand and it stuck closed as well. Recently, I had the transmission replaced by a qualified garage who I trust. The car had been unstarted for about 3 weeks while the transmission was built and shipped to this garage. On the test drive for the transmission, the thermostat stuck shut and a proper test was not conducted. The tech called me and told me what had happened and recommended that the thermostat be replaced. I told them to go ahead, maybe they know a better way to purge the cooling system. I picked the car up and drove it home, checked out fine. The next day I started it up and the new (4th) thermostat is stuck shut. I mean the temp gauge is almost pegged and the radiator is stone cold, the heater is blowing cold air.....can anyone offer some advice?
Please help! Thanks!
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Sorry about your LT-1, but there may be a problem inside the housing. The next time you remove it, simulate how it sits, and if the thermostats you are using have any extra metal on the crimping flanges poking out a little bit. you can usually file things like that off.
To the original poster............Your car should not run anywhere lower than 180 degrees. If your car is running that low, the emissions package won't be working correctly and the cylinder heads will not be properly heated and the cylinders will not be of the proper shape when your car is running.
If your car is basically stock, or near stock with the original bore, pistons and heads, you may be your engines' worst enemy by not getting it up to proper temp.
There is a fallacy running around that cars should run at 160 degrees. This is incorrect.
Originally, 50 years ago, it was desireable to have the engine run as cool as possible.
The reasons are numerous;
1. pressures in the cooling system were regulated by a 7 pound cap or less pressure.
2. all radiators were vertical, and the time it took for the water to get from the top to the bottom was less, and therefore did a lousy cooling job.
3. fuel metering was not accurate and engines sometimes got hot due to lean condition.
4. intake manifolds were not scientifically constructed, but only used as a method to get fuel and air to the cylinders without leaks.
5. carburetors were not designed for optimum efficiency.
6. carburetors had no way of circulating the fuel to eliminate vapor lock
7. fuel blends were lousy, and detonation occurred frequently with a warmer than usual engine.
8. Engine speeds were higher because few people had overdrive, so a cooler engine meant not encompassing temperature related operating problems.
End result: smog, air pollution, unhealthful environment, etc.
The answer...........
1. more complete combustion
Meaning:
A. higher combustion temps
B. more efficient radiator/cooling systems with crossflow radiators, higher pressure water system caps, coolant blends, overflow recovery, more efficient water pumps, etc.
C. elevated water/cooling temps to more stabilize engine cylinder operating environment
D. Exhaust gas recirculation
E. more efficient fuel injection systems
F. Catalytic converters
G. air pump systems to light off the converters and add air to the exhaust to more completely burn the exhaust.
H. Fuel vapor control to eliminate fuel evaporation into the atmosphere
I. additional vehicle monitoring
J. redesigned combustion chambers
K. redesigned cam profiles
L. redesigned pistons
M variable valve timing
N. optimum computerized timing and fuel schedules
without an engineering degree and proper testing, documentation, experience and financial backing, arbitrarily modifying your car is not the way to go. Your car was meant to run at 200 degrees consistently with all smog controls in place.
If you change your temps, your smog controls need to be reevaluated and calibrated and modified to run at your new selected temperature along with fuel scheduling and timing recalibration.
To the original poster............Your car should not run anywhere lower than 180 degrees. If your car is running that low, the emissions package won't be working correctly and the cylinder heads will not be properly heated and the cylinders will not be of the proper shape when your car is running.
If your car is basically stock, or near stock with the original bore, pistons and heads, you may be your engines' worst enemy by not getting it up to proper temp.
There is a fallacy running around that cars should run at 160 degrees. This is incorrect.
Originally, 50 years ago, it was desireable to have the engine run as cool as possible.
The reasons are numerous;
1. pressures in the cooling system were regulated by a 7 pound cap or less pressure.
2. all radiators were vertical, and the time it took for the water to get from the top to the bottom was less, and therefore did a lousy cooling job.
3. fuel metering was not accurate and engines sometimes got hot due to lean condition.
4. intake manifolds were not scientifically constructed, but only used as a method to get fuel and air to the cylinders without leaks.
5. carburetors were not designed for optimum efficiency.
6. carburetors had no way of circulating the fuel to eliminate vapor lock
7. fuel blends were lousy, and detonation occurred frequently with a warmer than usual engine.
8. Engine speeds were higher because few people had overdrive, so a cooler engine meant not encompassing temperature related operating problems.
End result: smog, air pollution, unhealthful environment, etc.
The answer...........
1. more complete combustion
Meaning:
A. higher combustion temps
B. more efficient radiator/cooling systems with crossflow radiators, higher pressure water system caps, coolant blends, overflow recovery, more efficient water pumps, etc.
C. elevated water/cooling temps to more stabilize engine cylinder operating environment
D. Exhaust gas recirculation
E. more efficient fuel injection systems
F. Catalytic converters
G. air pump systems to light off the converters and add air to the exhaust to more completely burn the exhaust.
H. Fuel vapor control to eliminate fuel evaporation into the atmosphere
I. additional vehicle monitoring
J. redesigned combustion chambers
K. redesigned cam profiles
L. redesigned pistons
M variable valve timing
N. optimum computerized timing and fuel schedules
without an engineering degree and proper testing, documentation, experience and financial backing, arbitrarily modifying your car is not the way to go. Your car was meant to run at 200 degrees consistently with all smog controls in place.
If you change your temps, your smog controls need to be reevaluated and calibrated and modified to run at your new selected temperature along with fuel scheduling and timing recalibration.
Last edited by coupeguy2001; Jan 17, 2011 at 11:42 AM.
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
To the original post.
Don't know the answer on an L98 (yet) but I can tell you all of my last three GM's (all Pontiac's) had an issue with intermittant warnings of low coolant. All 3 times it was the sensor, in the Bonneville it was right on the overflow tank. On the GTP I was told it was also on the overflow tank but you had to pull the fender to get to it so I left it
On at least an 87 this sensor shows as on the rad. It is resistance based, measures the resistance of the coolant and assumes that too high a value means it isn't totally submerged. If your knew coolant is either the wrong type, not enough water, or the sensor is gunked up, it won't read a enough 'short' to think it is submerged.
Greg
Don't know the answer on an L98 (yet) but I can tell you all of my last three GM's (all Pontiac's) had an issue with intermittant warnings of low coolant. All 3 times it was the sensor, in the Bonneville it was right on the overflow tank. On the GTP I was told it was also on the overflow tank but you had to pull the fender to get to it so I left it
On at least an 87 this sensor shows as on the rad. It is resistance based, measures the resistance of the coolant and assumes that too high a value means it isn't totally submerged. If your knew coolant is either the wrong type, not enough water, or the sensor is gunked up, it won't read a enough 'short' to think it is submerged.
Greg
Race Director
Joined: Oct 2005
Posts: 11,770
Likes: 175
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
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5th Gear
Joined: Sep 2012
Posts: 5
Likes: 0
From: Virginia
89 Corvette Low Coolant warning
The cooling system is a closed system. Burp the radiator system and make sure the coolant overflow container is half full or so after coolant repairs. Start your engine let it idle to operating temperature and shut if off. As the cooling system cools it will suck water from the overflow tank. After the engine has cooled, check the overflow tank per specs. This process may be required 1 or more times until the issue is resolved. If this does not resolve the issue, check for leaks or a bad sensor.
