Running hot during summer
Thread Starter
4th Gear
Joined: Mar 2014
Posts: 4
Likes: 0
Running hot during summer
I just got a 84 corvette and know that they run a little hot during summer in Arizona (my dad used to own one). Do you guys have any tips of things I could try to make it run cooler? Thanks
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Your question is pretty vague. "A little hot" (?) What does that mean? 'Vettes shoudl run ABOUT the same temp in AZ as most other places in the summer.
Also, do you actually have a problem that needs solving in your particular car?? I didn't see you post anything about a specific issue w/your car.
If the cooling system is working properly, it should run around 200*F on the road (moving fast enough to provide air flow), and cycle between ~215* and 230*F when stationary/idling due to the fan's setting. This should be the case whether you're in AZ or Montana.
Also, do you actually have a problem that needs solving in your particular car?? I didn't see you post anything about a specific issue w/your car.
If the cooling system is working properly, it should run around 200*F on the road (moving fast enough to provide air flow), and cycle between ~215* and 230*F when stationary/idling due to the fan's setting. This should be the case whether you're in AZ or Montana.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Have you done a cooling system service? i.e. flush and new coolant? Is the thermostat original to the car? Are the radiator hoses original or old? Is the coolant in there a bright green or is it milky and maybe a brownish (dirty) tint? Is the radiator cap old?
You mentioned a new air dam; does the car not have the OEM air dam or is it damaged? You do need the OEM style air dam so air can be directed up into the condenser and radiator.
What temps are you seeing? C4's run warmer because that's designed into the cooling system as a way of burning off emissions.
One thing that many people overlook is whether or not the radiator and A/C condenser is clogged up with dirt and debris. Look up behind the front license plate where you can see the condenser. Chances are theres lots of dirt that's clogging the fins so air can't flow thru. That lowers the amount of air going thru the radiator.
Also look between the condenser and radiator for debris. With a little effort, you can vacuum out anything in that gap. Then use a garden hose to force out any dirt in the radiator fins.
I would suggest a complete cooling system service. Drain the old coolant and replace with water. Run to operating temp and drain. Do this twice more. The idea is to get out as much of the old coolant out as possible. I would also replace the upper and lower radiator hoses if they are more than 6-8 years old. Replace the thermostat with on eof the correct temperature. Replace the cap if necessary. Then fill the system with a 50-50 mix of a good ethylene glycol (green) coolant and distilled water.
You mentioned a new air dam; does the car not have the OEM air dam or is it damaged? You do need the OEM style air dam so air can be directed up into the condenser and radiator.
What temps are you seeing? C4's run warmer because that's designed into the cooling system as a way of burning off emissions.
One thing that many people overlook is whether or not the radiator and A/C condenser is clogged up with dirt and debris. Look up behind the front license plate where you can see the condenser. Chances are theres lots of dirt that's clogging the fins so air can't flow thru. That lowers the amount of air going thru the radiator.
Also look between the condenser and radiator for debris. With a little effort, you can vacuum out anything in that gap. Then use a garden hose to force out any dirt in the radiator fins.
I would suggest a complete cooling system service. Drain the old coolant and replace with water. Run to operating temp and drain. Do this twice more. The idea is to get out as much of the old coolant out as possible. I would also replace the upper and lower radiator hoses if they are more than 6-8 years old. Replace the thermostat with on eof the correct temperature. Replace the cap if necessary. Then fill the system with a 50-50 mix of a good ethylene glycol (green) coolant and distilled water.
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
oh, for pete's sake; to maximize a chevy's cooling system, first you've got to convert your car from a fifty stater dsigned to survive Alaskan winters (and a little bit of everything else in all the other 49 states) to one designed to survive Arizona summers.
DO do everything suggested before. But to truly maximize your engine cooling potential you've got to delve deeper.
First, maximize flow from your water pump. Pull the water pump, if it's got a samped sheet metal style "paddle wheel" impeller, and 90% do, toss it. Spend the bucks and get a high performance water pump with a cast, or machined impeller that has curved vanes. Weiand Team G makes one, other's do also, be prepared to spend some money, this is the heart of the system.
One of the drawbacks of the stock Chevy cooling system is that it does NOT send all the hot water to the radiator where it needs to go so it can be cooled.
Look at the front of the block where the pump mounting bolts screw in. Notice a third hole (drivers side ?) and a matching hole in the pump casing ? This is a bypass circuit that diverts water from the block to the suction side of the pump and back into the block, thereby bypassing the radiator. Granted, this is important in the cold Alaska mornings, in that it helps warming up the engine, but in the heat of Arizona you want all the water sent directly to the radiator. A common racing modification to aid cooling was to block this opening; a good high performance water pump may already have the port in the pump casing already blocked off.
The quest to force all the hot water into the radiator is not yet over. A portion of the hot water is taken from the thermostat housing (from below the thermostat) and sent to the heater core, splice a shut off valve into this hose and close it during hot weather. The hot water that normally goes through the heater core is NOT cooled during summer operation and returns uncooled to the suction side of the pump, once again being bypassed around, and not through, the radiator.
In truly hot climates a themostat becomes just another possible failure point. DO NOT eliminate it entirely, instead, clip out the center "bulb" and disc portion and reintall the outer ring as a restrictor plate; or go online, circle track race suppliers sell ready made restrictor plates in a series of inside diameters to fine tune your cooling system.
If you do use a thermostat, drill a hole , 1/8th inch diameter, in the outer ring; a high performance thermostat will probably already have one; this prevents any entrained air from becoming trapped underneath a closed thermostat; but again I'd go with a fool proof restrictor plate.
Finally, to maximize water pump performance during the worst conditions, such as slow speed, stop and go traffic, investigate installing a larger pulley on the engine, or a smaller one on the pump, thereby raising pump speed during crucial slow speed operations. This is just the opposite of what "performance pulley" sets are designed to do.
DO do everything suggested before. But to truly maximize your engine cooling potential you've got to delve deeper.
First, maximize flow from your water pump. Pull the water pump, if it's got a samped sheet metal style "paddle wheel" impeller, and 90% do, toss it. Spend the bucks and get a high performance water pump with a cast, or machined impeller that has curved vanes. Weiand Team G makes one, other's do also, be prepared to spend some money, this is the heart of the system.
One of the drawbacks of the stock Chevy cooling system is that it does NOT send all the hot water to the radiator where it needs to go so it can be cooled.
Look at the front of the block where the pump mounting bolts screw in. Notice a third hole (drivers side ?) and a matching hole in the pump casing ? This is a bypass circuit that diverts water from the block to the suction side of the pump and back into the block, thereby bypassing the radiator. Granted, this is important in the cold Alaska mornings, in that it helps warming up the engine, but in the heat of Arizona you want all the water sent directly to the radiator. A common racing modification to aid cooling was to block this opening; a good high performance water pump may already have the port in the pump casing already blocked off.
The quest to force all the hot water into the radiator is not yet over. A portion of the hot water is taken from the thermostat housing (from below the thermostat) and sent to the heater core, splice a shut off valve into this hose and close it during hot weather. The hot water that normally goes through the heater core is NOT cooled during summer operation and returns uncooled to the suction side of the pump, once again being bypassed around, and not through, the radiator.
In truly hot climates a themostat becomes just another possible failure point. DO NOT eliminate it entirely, instead, clip out the center "bulb" and disc portion and reintall the outer ring as a restrictor plate; or go online, circle track race suppliers sell ready made restrictor plates in a series of inside diameters to fine tune your cooling system.
If you do use a thermostat, drill a hole , 1/8th inch diameter, in the outer ring; a high performance thermostat will probably already have one; this prevents any entrained air from becoming trapped underneath a closed thermostat; but again I'd go with a fool proof restrictor plate.
Finally, to maximize water pump performance during the worst conditions, such as slow speed, stop and go traffic, investigate installing a larger pulley on the engine, or a smaller one on the pump, thereby raising pump speed during crucial slow speed operations. This is just the opposite of what "performance pulley" sets are designed to do.
