VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Almost Over Heating

Looking to get everyone's opinion. My car has always ran near or just above the 180 mark. As soon as I get in town it climbs up near the red lines on the gauge. I had the shop I use back flush the system and remove the thermostat and that very minutely done any thing. My goal would be to drop the temp to a more comfortable level. I took an extra radiator to a shop today to check on a oversize core to the tune of $800.00. I don't mind spending that but there is no guarantee this will help me either. I remembered from years past that the trucks used a larger fan blade so that is the direction I am thinking of taking now. The passenger blade is 16" and I see for commercial there is an 18" listed. What is everyone's thought(s).

The radiator shop should be able to flow test your radiator. If it is ok there is no sense in changing it to fix what is not broken.

The 1947 engine was not prone to overheating. A larger fan will be covering up a problem.
I would suspect the block cooling system passages are filled with rust. Boiling out the block in a rebuild does not always remove the rust.I would begin by removing the welch plugs and the left side of the block doing the rear one first for a test.
A160 termostat would be recommended.
Using an infra red temp gun could locate hot spots in te cooling sytem.

I agree with Gene that the passages in the block and head are probably full of rust. A bigger fan and /or radiator will not solve the problem.

All of the above is good advice.

You may want to advertise in parts wanted for a NOS radiator,

Do some more checking the system by:

a. Pull the radiator. Use a garden howe and then fill it up by holding your hands over the inlet and outlet, After filling let go of the lower outlet. You should see a rush of water about four to five inches tall and no sucking sounds. If the rush of water is lame and doesn't clear immediately then you have blockage in some of the flues. The more flues blocked the slower the of water flow. Use a air compressor chuck and a rag at the outlet and while using the garden hose again flush the radiator several times. This will only clear some of the flues. Better, You may be able to have your radiator shop boil and rod it. Use "Solder Seal" or some other product for tiny holes found on testing for leaks.

b. Take the thermostat out and flush the block by blowing compressed air back through the petcock on the lower left side of the block until it runs clear.. Gene's recommendation of taking out the Welsh (freeze) plug is sound/

c. Check for blown head gasket, head and block cracks by filling the system (radiator back in with lower hose(s) in place, Fill to top of engine hose neck. Trip the fan belt. Then start the engine. and look for any bubbles. Bubbles could be from slight to major, If no bubbles water should just sit there.

d. Check for bugs in the core.

e. Gene;s recommendation on the temperature of the thermostat is sound but I would go with a 180 degree one, More normal. The engine is mechanical and unlike flesh it does best when around 180. The lower temperature is just so you feel better about ol' Betsy, Nothing more.

Now after doing the above tests you are ready to make a decision on core /radiator replacement. Try Parts Wanted here and Hemming Motor News.

Good luck.

Charlie

BTW: I agree with others who say the bigger fan and over-sized radiator core are just masking the problem.

You can check the efficiency of the radiator with a heat gun. Check the temp at the top near the inlet and at the bottom near the outlet. If there is a big difference (40-50 Deg) then the radiator is doing it's job.

Still working on my issue of running to warm for me. I have bubbles showing in the coolant in the radiator. They are that bad that they make the warm foam when running at a fast idle. I done some research and got the feeling I may have a head gasket leaking. The oil is not milky so I feel sure I am not getting any water in it. I bought an engine block tester and done the blue fluid thing and it does not turn the fluid yellow so should not be getting combustion in the cooling system either. At a lose and need some suggestions. The car runs great just runs to warm for my comfort.

Any sign of weeping/leaking anywhere? Air can be drawn into the coolant anywhere on the suction side of the water pump contributing to your bubbles. Straight water that gets above 180ish will also get bubbles. Are you running coolant or just water?

As for the running on the hotter side - Air in the coolant can contribute to this but ideally go up a few posts and follow what Gene suggests as you may have two independent problems.

I have the bubbles right from the initial start. As for the water pump are you referring to the gasket on the back of it?

I was referring to anything on the vacuum side of the water pump that could allow air to be sucked in - Waterpump gasket, shaft area, hoses, clamps, etc. Air can travel through smaller holes than liquid but it's likely you will find some crust, wetness or other evidence of coolant leaking.

Again, follow through on Gene's post above especially checking with a Infrared heat gun as it sounds like the cooling system is inefficient overall and a gun will show you beyond a doubt what is going on. If you search old posts, you will find that most of the time the problem is due to the engine block being plugged with rust and a typical flush will not remove it. Gene mentions how to clean it the post above.

Sounds likea head gasket or cracked head.

Borrow a radiator pressure tester and see if it holds pressure in the system or not.

I will try that. I left the block taster stuck (which sealed things off) in the radiator today and it eventually build up pressure and bulbs up into the blue fluid.

Shorty,

Did you try test "C" in my suggestions above. It will confirm whether you have a blown head gasket, cracked head or block.

If you have bubbles after the above test then pull the head and examine those three items. Most any machine shop can magna-flux (sp) the head for cracks. Those usually show up new the spark plug holes.

Good luck,

Charlie

I agree with Gene but also want to remind all of the importance of doing an ADVANCED SEARCH of our past posts whenever they are dealing with problems. For this topic using the SEARCH TERMS +cooling +system and the DISPLAY NAME Mike Buller or Chev Nut leads one to a lot of good advice. Here is my 2 cents:

Overheating Issue.

Good luck, Mike

Thanks for the help everyone. I will be borrowing some tools and do the testing in the near future and will keep everyone up to date on the results. Hopefully the weather works with me. If not may take a bit longer.

Done some testing today. Done a compression test and they are from front to rear: 130-135-135-135-130-125. Also done a pressure check on the radiator with 8lbs of pressure and it held for about 3 hours. Hopefully will get a chance to do some of the other things next week. Talked to the local mechanic I work with and he feels maybe I need to let the block test fluid on top of the radiator longer than what I did. Will let you know how I make out.

Ok guys I need more directions. I done Charlies C test today of flipping the fan belt and my bubbles are gone. Where do I go from here? I see no leaks. Hoses don't show any leaking. Done the block test again yesterday and left the fluid on top of the radiator for over an hour and it does not change color.

Shorty,

The bubbles have to be coming from somewhere when its running. The usual suspects are in this order:

a. Head gasket.

b. Head cracked. May need to get hot enough to expand the crack.

c. Block cracked. (Ditto)

The length of time for either to show up is also in the same order but may be skewed owing to how bad each item is blown or cracked.

I don't know how much time is required for the bubbles to show up on your engine but perhaps you didn't run it long enough. May try again. If you do don't worry about harming the engine but do stop when the solution starts coming out the the head owing to heat expansion. If no bubbles by then then maybe none of the usual suspects are guilty.

Boiling solution down in the block or head may produce bubbles, so Genes suggestion of plugged passages may be the culprit.

The water pump and radiator are not usual suspects for producing bubbles. Both will leak but not cause bubbles as far as I know or have heard.

Good luck with it. Bout cot me stumped.

Charlie

Just a bit of an update and another question. I finally got around to replacing the water pump and happy to say the bubbles in the radiator are gone. Hard for me to believe but that is great. I also advanced the timing and it done a lot for my heating issue. The gauge still comes up quite a ways but holds there when sitting at a red light on these hot days. The gauge may be off some so I am good with this also. Now my next question is the car idles beautifully but as I slowly accelerate the engine, when I get to what I would consider just a little more than fast idle I have what I would call a flop in the engine. Not sure what to try to correct my issue. I think this flop also happens when I am driving but not as noticeable. Do I need to check carburetor? I am also not sure about my vacuum advance either, not sure it is moving. Any help is appreciated.

Hi Shorty,

Please start a new thread each time you change the topic of your question. It is confusing for users to see a heading that is no longer about the topic. Many might avoid reading your posts as they have no interest or expertise in your original question.

Thanks, Mike

Water pumps drawing air into the coolant is a very common problem. If the pump leaks water then it is certain with low pressure cooling systems that it will draw air. Even if it doesn't leak coolant air can be drawn in. Air takes up coolant space which lowers heat transfer and expands greatly when engine is shut off pushing out more coolant.

Even pressurized systems can draw in air but potential is reduced by the cooling system pressure.