Overheating

[old timer]

How about a list of gremlins ( sorry AMC guys ) that could cause an overheating problem . If you know some of the causes you might find it easier to find a cure .

 

[rolling_Thunder]

incorrect radiator cap
collapsing lower radiator hose
weak water pump
water leak somewhere
poor timing
poor air/fuel ratio
bad fan clutch
no fan shroud

 

[68GTS340]

loose or missing fan belt, retarded timing , having way to much fun doing burnouts.

 

[GTXperience]

To add onto the others above: Passage ways (especially in the block) partially blocked. Incorrect fan spacing. Improperly installed electric fans. Corroded blades (causing a weak flow as Thunder mentioned). I have also heard of inefficiency with aftermarket high volume systems that don't allow an efficient heat transfer.

 

[Pistol Pete]

Plugged up cooling fins on the radiator.

 

[63hemipolara]

No thermostat, no shroud, tranny fluid running through the rad, restrictive thermostat

 

[Revhendo]

Yep, I have run into the "High Flow" waterpumps pushing the coolant thru too fast. Mismatched pulleys or those high-po underdrive pulleys can cause a few headaches also.
Down at our shop, we put together a couple of cars back to back with March pulleys, E-brock high flow pump and a crossflow aluminum radiator that had a triple baffle in it. Everytime the thermostat opened, the thing would suck the lower hose closed. The boss forgot to mention the ultra trick radiators he got us. It took awhile to sort everything out. Just goes to show that you can outsmart yourself without even thinking about it.

Rev.

 

[69 Runner]

To many fins.
Some of these new "max cool" type radiators don't work well with our cars because the fin count (number of fins per inch of radiator core) is much higher than the original radiators had. They don't seem to flow enough air, even though they're supposed to work better BECAUSE of the higher fin count.

Also, I've seen an impeller get twisted off inside a pump. No noise. No leak. Just a hot running motor, with half the radiator hot, the other half cold.

 

[Roadcuda]

To add onto the others above: Passage ways (especially in the block) partially blocked. Incorrect fan spacing. Improperly installed electric fans. Corroded blades (causing a weak flow as Thunder mentioned). I have also heard of inefficiency with aftermarket high volume systems that don't allow an efficient heat transfer.

If there is a partial block passage blockage, is there a way to determine that, and could it be cleared without removing and tearing down the engine?
My 383 will run at normal temps while driving but if I have to sit still for more then a traffic light cycle, the temp will rise 20-30 degrees. It will cool down again once I get moving again. I've had the 26" radiator cleaned, have a shroud, new 180 thermostat, new hoses, and it does have good water flow. Also, I installed an electric fan with the temp probe at the top center of the radiator, set to go on at 160. When the water temp goes up over 200, the fan never goes on. This car has both the dash temp gauge, and an aux gauge which both show the temp going up. Any ideas?

 

[eldubb440]

i ran a 160 stat thinking it would run 160.........but the coolant didnt stay in the radiator long enough to cool, and it would shoot right up to 220...........put a 180 in it, and it held 180.

 

[69hemibeep]

If there is a partial block passage blockage, is there a way to determine that, and could it be cleared without removing and tearing down the engine?
My 383 will run at normal temps while driving but if I have to sit still for more then a traffic light cycle, the temp will rise 20-30 degrees. It will cool down again once I get moving again. I've had the 26" radiator cleaned, have a shroud, new 180 thermostat, new hoses, and it does have good water flow. Also, I installed an electric fan with the temp probe at the top center of the radiator, set to go on at 160. When the water temp goes up over 200, the fan never goes on. This car has both the dash temp gauge, and an aux gauge which both show the temp going up. Any ideas?

Roadcuda, put the sensor as close to where the water comes into the radiator as you can. Its been partially cooled in the middle! 210 at a light in the summer aint bad!

 

[hotrod98]

I've seen four core radiators that didn't cool as well as three core radiators.

Oh yeah, placing big pointy noses on daytona and superbird clones tends to cause overheating. I'll probably have to buy a couple of those $1200 aluminum radiator packages.

 

[62MAX]

I've seen four core radiators that didn't cool as well as three core radiators.

Oh yeah, placing big pointy noses on daytona and superbird clones tends to cause overheating. I'll probably have to buy a couple of those $1200 aluminum radiator packages.

Not really and not a clone.Original radiator,fan and clutch.180* thermostat.Stays there all the time.Just make sure you have the shield that goes from the bottom of the core support to the K member.

 

[696pack]

How about a list of gremlins ( sorry AMC guys ) that could cause an overheating problem . If you know some of the causes you might find it easier to find a cure .

The biggest problem that I see with many cooling systems that have been changed over the years from the factory set up is that many are trying to move the fan too close to the radiator. What will work the best is with the fan basically 1/2 in and 1/2 out of the rear edge of the fan shroud. If you have the fan too close to the radiator the fan is basically "windmilling" the air around inside of the shroud. With the fan set back it creates a suction in the shroud pulling the air through the radiator rather than just milling the air around inside the shroud.

 

[62MAX]

The biggest problem that I see with many cooling systems that have been changed over the years from the factory set up is that many are trying to move the fan too close to the radiator. What will work the best is with the fan basically 1/2 in and 1/2 out of the rear edge of the fan shroud. If you have the fan too close to the radiator the fan is basically "windmilling" the air around inside of the shroud. With the fan set back it creates a suction in the shroud pulling the air through the radiator rather than just milling the air around inside the shroud.

Exactly right!

 

[69hemibeep]

Exactly right!

Perfect!:yes:

 

[696pack]

Yeah, it seems like many people want to try and reinvent the wheel. The auto manufacturers hire engineers, spend lots of money and time testing these types of things for use on the 100s of 1000s of cars they produce per year to work without problems, but there are always a few guys that seem to think they have a better mousetrap. OTOH, if we didn't have innovators there are a lot of the cool things that we DO have on our hotrods.