Overheating

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pawillie

Member
I flushed engine and radiator several times and still overheats shortly after start up, during idle. Top radiator hose gets hot but bottom hose cool to barely warm. Could problem be engine or radiator?
 
Hello, bad head gasket? Look inside radiator and see if bubbles indicate leaking head gasket, another possibility is clogged radiator, usually spits out water, slipping fan belt a possibility.
 
You didn't mention history of your car, but if the water pump has had more than its share of grease pumped into it by previous owners, the excess grease can accumulate in the radiator and clog the tubes. You probably should take it to a reputable radiator shop for evaluation and proper cleaning.
 
If the bottom radiator hose is cool as the engine overheats, you are not circulating coolant. Flush the radiator and engine block. Even without a belt on the engine, there should be enough thermal circulation to keep the engine cool at idle. As said above, check for bubbles in the radiator when running. You should also be able to see water circulating if you look into the radiator when its running.
 
What is the actual temperature of the coolant?
Place a dial probe type of meat thermometer into the coolant and let us know what the temperature actually gets to.
 

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Let’s not forget how the system flows. It’s a system that pushes up, letting it fall down the radiator. So the upper hose should be quite a bit warmer than the lower, return hoses.

Nothing here is cause for concern. Flush the system all you want, it’s not indicative of much.

Provide us with some coolant temperatures at idle, operating and other conditions.

We need details! Meat thermometers won’t provide it either.
 
Hitman said:
Let’s not forget how the system flows. It’s a system that pushes up, letting it fall down the radiator. So the upper hose should be quite a bit warmer than the lower, return hoses.

Nothing here is cause for concern. Flush the system all you want, it’s not indicative of much.

Provide us with some coolant temperatures at idle, operating and other conditions.

We need details! Meat thermometers won’t provide it either.
Click to expand...

I fully agree. The BEST way is with an infra red temperature gun. Measure at the top and bottom of the radiator at say, 3 places across the width, then let us know the results.
 
Curious as to why you guys think that the meat thermometer wont measure the temperature of the water. Seems very accurate to me and isn't subject to electronic variances and battery failure of the infrared thermometers.

I realize that it wont take the temperature of the various areas on the face of the radiator but its taking the temp of the coolant as its coming straight out of the engine at its maximum temperature.
 
Sounds to me there may be a large cotton mouse nest in top tank of radiator that just won't flush out with water. Take off radiator and shake it upside down, listen and look, use a hooked wire and fish around in tank. This actually happened to me.
 
Perhaps we will never know as the original poster hasn't visited the site since he posted his question.
With him only having 10 posts it could just be a case of a new owner having the radiator too full and the expanding coolant pushing out of the cap / overflow tube and it looking like an overheating situation.

Still curious on Hitman's and Synchro's reasoning on why a dial type thermometer wont work for telling what the temperature of the coolant is.
 
I’m an old man now and have only been running Model A’s since the early nineteen sixties. With that somewhat limited experience. My guess would be your radiator.

You can spend as much time as you like measuring how hot things are. Talk about how the system should be working. Grease, water pump, whatever.

It’s your radiator! There could also be some other issues that are adding to the problem.

“But”. I have never seen a Model A that has not been improved by adding a new or re cored radiator.

If your planning on driving the car? It will be money very well spent.

Front end, brakes, springs, shocks, radiator, and water pump. You can spend anything you want on paint, interiors, high compression heads, and jewelry for your car, but these six things must be right.

Sorry. I got my soap box out again. I’m old now, so please forgive me. Model A’s and Lionel trains are really the only things that keep my attention.

Enjoy. Haze Gray and Underway. Gator Freighter! Beach Masters Unit Two.
 
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I agree with 1 crosscut. I wish people would come back on the site and tell us what
worked and what didn't. It would help so many of us less experienced Model A'er's.
 
I recently had an overheating problem with my Victoria. On a trip to the last New England Meet in Connecticut from my home on Long Island, my Victoria boiled away 4 gallons of water.

I used a bottle of Thoro Flush from Snyder's and it successfully cleaned-out my cooling system.
 
radiator fills to 11/2 gallons and drains in 4 sec. Doesn't seem clogged. However, engine itself only fills to about 5 quarts and I believe it holds 6 quarts. Must have a block in water jacket. I filled engine with Evapo-Rust and letting soak for a couple of days. Any other suggestions?
 
Your radiator is draining at about half of the flow rate that the cooling system is designed for.

The thermal siphon coolant flow as designed is approximately 32 gallons per minute out of the engine when at running temperature. Remember, even with a water pump, the Model A is designed to also use thermal siphon flow. The Model T just used thermal siphon flow for cooling.

Your engine most likely needs to be cleaned, but your radiator appears to also be somewhat blocked.

One and one half gallons should drain out in under three seconds. It doesn’t take much reduced flow to cause overheating. It appears that you have about one third reduced flow.

Enjoy.
 
Thanks for the info. definitely will give attention to the radiator as suggested. Will give the Evapo-Rust awhile to soak through the engine. Not looking forward to taking it out of car.
 
Pawillie, I have worked on and played with these cars since 1961, and in my experience periodic flushing and testing the flow rate, and checking your temps with a temperature gun, cheap and effective from H.F., will guide you in what you should do. In 74 years of owning, fixing, buying, driving, and selling some 25 Model A’s in all kinds of conditions, I have only had to replace a radiator twice. One because I accidentally punched a hole in it, one because it leaked badly and cost less ro replace than repair. I like HItMan’s suggestions. If through the suggestions above and your experience with them you determine your radiator is good, make the relevent repairs and adjustments as you see fit, and absolutely avoid removing the radiator in any way you can!
 
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