VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Overheating issue

I have a 1950 Chevy Styleline Deluxe with a 216 engine. I have replaced the radiator, water pump, thermostat, etc., etc. Unfortunately. when I start it and it runs for 10 minutes or so it overheats. Not sure what the problem is but any ideas would be much appreciated. Thanks, Mike

Are you physically measuring the coolant temp and it's too hot or is it just overflowing the radiator? If it's simply overflowing the radiator you might just be overfilling it. Hot liquid expands and has to go somewhere. That issue is much more common that most people think. I'll move this to a technical forum for you.

Drill a 1/8 inch hole in the flat flange of the thermostat or just remove the themostat and give it a try.
Some times the modern style thermostats do not open in the old non-pressure type systems.
That was my problem in my 1950..

When you say "overheats" are you referring to what the rad is doing or what the temperature gauge is showing you. If it's the temperature gauge climbing toward the H mark, take the car for a drive and see if the gauge comes back to the middle mark. If it does, your '50 is behaving properly. If not, check for a collapsed rad hose. If you're still having a problem, go back over the rad, water pump and thermostat to ensure they are operating properly. Even "new" ones can be bad.

The radiator did overflow, so maybe I did over fill originally. However, even now with the lower level the temp rises way higher than it should and that is at a fast idle withe a fan blowing into the radiator. I guess I need to check the thermostat first. Then go from there. Thanks for all the suggestions.

No one has mentioned that the problem could be accumulated rust INSIDE of the engine... The engine must have been overheating Before you replaced all those things... otherwise, why did you replace the radiator and water pump, etc...???
Even flushing the engine often does not remove the rust in the water jackets, of the head & block... Did you open up the engine and clean out the water passages..??

The car sat for 20 years, and I fear you may be correct WildernessTruck. I would like to try everything I can before tearing into the engine. The radiator was obviously shot, and I relaced other parts because it was time. Really hoping I don't have to do a major. Also, the engine was rebuilt 40 years ago and there is only a couple of thousand miles on it since then. I'm sure sitting for that long was not good so we will see. Thanks for the good input. Mike

I suggest disconnecting the radiator hoses, remove the thermostat, and flush the engine backwards and forwards with a garden hose.

If the overheating still occurs after that exercise, the next step I would take is to remove the head off the engine. This will expose the water jacket holes in the head and the block. You can scrape the crud to stir it up with a screwdriver and coat hanger wire, and then vacuum it out. The areas prone to rust accumulation are around the rear cylinders.

Both of the above suggestions can be performed without taking the engine out of the vehicle.

Keep us posted about your progress.

Fingers crossed, Dean

Thanks Dean, I will definitely try the flush option and if nothing else works I will have to go to plan B. Thanks for the suggestions. Mike

Hopefully you do not have a real overheating problem. Unfortunately that typically is not the situation especially if an engine has set for a long time.

I was able to “save” a large amount of work on my ‘37 by flushing the block in 6 directions.

I removed both the thermostat and the water pump. I made an adapter plate that bolted to the front of the block where the water pump mounts.

I spent a lot of time finding various plumbing adapters so I could connect a garden hose at the thermostat housing outlet, the water pump adapter plate, and the drain port at the rear of the ranging block. Plus I had caps to block off each one of them.

It was a messy process but worked. I never had overheating issues.

I would be cautious about running the engine too much before trying to flush it. You run the risk of filling your radiator with crud from the engine.

Thanks for the tips Rusty. Mike

Well, it's my experience that my advice won't be used but here goes anyway. Try these thing in order:

a. Take the top hose off and take thermostat out and replace the housing. Trip the fan belt off so that the water pump will not work.

b. Fill the engine up with water til it's running out the thermostat housing. Let it sit there.

c. Observe the water level at the thermostat housing while someone else starts the engine.

d. Is the water in the housing gushes out at the rate of a cylinder or tow rotates on the crankshaft then you probably have a blown head gasket. If it is small bubbles then it is probably a cracked head or block. If no movement then the block, head and gasket are ok.

f. take. the bottom hose off at the lower hose so that water runs out there. Use a garden hose to fill the radiator. If the water backs up the the radiator is stopped up to the point that it has insufficient capacity to handle the water.

(If "f" is observed get an air compressor and flush the radiator from the bottom to the top. Use a rag to help you get maximum pressure as you reverse flush the block. As with the radiator doe it until there is no rusty stuff coming out. When shooting air up through the block do it until the water runs clear. Using a coat hanger may help loosen some crud but not much.)

g. If none to the above helps then find a radiator shop that will boil and rod out the flues of the radiator. If you have leaks after boiling and rodding most can be soldered up. If the ten lbs of pressure shows tiny Leakes in some flues, you can use some product like solder seal to take care of them.

H. Your problem is probably not the water pump. Most issues with the water pump is found when they leak.

Good luck with it and let us know how it goes.

Best,
Charlie

Charlie... He has a brand new radiator....

Oops. Missed that. Sorry. It may apply to others though.

Thanks,

Charlie

Charlie might be on the right track. I am concerned that the new radiator is already compromised due to all the crud in the block and head.

Ok, thanks guys! I will do what I can to flush the block and see if I get any results. Charlie, that's a very thorough explanation of what I need do and much appreciated. It will be a few days before I get to it but will definitely report back about the result. Thanks again for the help. Mike