VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 1952 235 engine cooling problem

Engine newly overhauled by a "respected shop". Has 650 miles on O/H. Radiator was r&r at time of O/H. Head was torqued at 500 miles. Engine ran fine with temps just below center of gauge ever since first few break in runs. Has never heated up excessively since O/H until recently.

First "event" happened after driving car for 2-3 miles around town. Parked on street and while walking away, we looked back to admire the "Bluebird". It was dumping coolant on the street and steam was roaring from under the hood.


Since then, "SOMETIMES" it gets hot and does the steam engine imitation. "SOMETIMES" it does the steam engine thing when it is shut down and is NOT hot. We took the car to the shop as the engine job is still under warranty. They have done the following:
1. Changed thermostat
2. Changed radiator cap
3. Put in hotter thermostat
4. Installed coolant recovery tank.
5. Removed thermostat
6. Replaced the head gasket (no sign that it was bad but since it was a modern steel one they got a old copper style.) Inside of cyls and associated areas looked good. No sign of anything awry.

Engine still does the steam engine imitation. It seems like something is pressurizing the coolant passages. When it reaches critical mass, she starts blowing. No sign of bubbles in radiator but we are scared to look for very long...do not know when she will BLOW.

By the way, we do not run it hot on purpose. The shop had us "make it do it" so they could see the results. The results are quite dramatic. Honestly, the steam engine description is accurate. Especially since the install of the coolant recovery tank. Coolant and steam really ROAR out of the vent on the tank!!!

O/H shop said to send them the head so they can "pressure check" it.

What have you all to add????
Bob D.

P.S. This has forced us to drop out of the Chama Tour....RATS....maybe next year. :(

I don't understand why you put in a hotter thermostat, again adding a coolant tank and probably increasing the pressure on the system (converting the cooling system into a steam boiler) did you increase the radiator cap to a higher pressure one? I don't expect that your radiator can survive much longer. What exactly did they do to the radiator? and what about the water pump, maybe it isn't working properly, is it circulating with all the problems you are having maybe your engine coolant passages were not properly cleaned and you ended up with hot spots inside. Is the car a powerglide or standard? I am afraid the shop ("respected shop") is treating the old engine like a modern one with a high pressure cooling system. Why did you have it overhauled, and what did they do to the old babbit rod engine, if it was a 52 235? Boiling out the block may not have happened because of environmental rules, and it is loaded down with rust and crud.

By the way, Bev and Bob I checked out your profile and went ahead and authorized for you to have access to the VCCA members only forums on the Chat II site.

I also share your fondness for Ercoupe and C172 sold my 172M in 1983, it was time. keep us informed about that steam engine problem!

Very sorry you will not be able to see us in Chama. Will be a great tour.

I would look at the water pump first and then see if there is a problem with the head. When it overheats is the radiator uniformly hot at the top and gradually cooler as you check lower?

My '51 with PG acted like a geyser once. Took out the thermostat and didn't do it again. Have not yet replaced the thermostat as I didn't have another handy and could not check the one removed.

Bob,
Regarding the radiator, I don't know what "R&R" means. Rest and Recuperation? (Just kidding)

Loosen remove both hoses, take out the four bolts andslip the radiator out. Take a garden hose and fill the radiator to the top (have someone help you hold a hand over both outlets). When full turn off the hose so you can listen as well as observe. Release the water at the bottom outlet. The flow should initaially spring out to about three to four inches high. That's good. If not and the radiator only has a little initial rise and takes a while to empty, Listen for any prolonged sucking sound. You may have several flues stopped up. This means that the top tank needs to be taken off the radiator boiled and flues rodded. Any competent radiator shop can do this.

A reverse flush may help some but that only will free enough flues to take the pressure. It won't get em all.

If its not the radiator then take the thermostat out, replace the housing and fill it to the top of the housing. Trip the fan belt. Crank engine over while observing the water level. Should be no movement. If there is you have compression getting in to the water. Cracked head, head gasket or cracked block.

I doubt it is the water pump unless the impeller has separated from the shaft. Seldom happens.

Again let us know what the "R&R" means.
Best,
Charlie

Radiator was Removed and Reinstalled or Removed & Repaired??
During the overhaul the rust and crud in the block could have dried out, loosend up tumbled around, and when the car was run first few times rust could have been dumped into the radiator or fouled up a small passage in the block.

I would suspect the above also. When at running temperature the radiator should feel equally hot all over the surface. Feel the FRONT of the radiator with the engine running.

Check the bottom radiator hose, it should have a spring in it to keep from collapsing when the pump sucks.
Try gunning the engine, and watch the hose.
If this is the case, the engine will run cool at slow speeds and get hot at higher RPM.

Hi All,
On item 3 in my original post I "miss spoke". They put on a colder thermostat. Sorry.

The thermostat has been taken out for now to eliminate that troubleshooting step.

The new radiator cap is the same rating as the old one...4 lbs.

R&R radiator is Remove and Repair. A local radiator shop cleaned and pressure checked it.

I went out and started the engine and looked into the open radiator. What I can see of it, the radiator insides are clean. Water is definitely circulating (remember there is no thermostat). So water pump is pumping. Water warmed up at the top radiator hose and top of radiator. Water cooled as it went down thru radiator. Bottom of radiator and lower radiator hose was cooler than the top.

Car has Powerglide tranny.

I will not wrench on this project personally. I do not want to void the warranty. Mark, my local garage owner, who has been my mechanic for many years, has always backed up his work 100%. He is very specific about the fact that only he will work on a car if he is going to honor his warranties. Therefore, all of these suggestions are being printed out for him to read. Mark has other shops (some of them hundreds of miles away...keep in mind that Susanville is a little isolated in the Sierra Nevada mountains.) that he has developed faith in who do O/H's for him. His is a small father and son operation.

Mark has tried locate any crack or pinhole in a casting but so far no luck. The engine O/H shop wants him to send them the head so they can "pressure check" it. Mark's communication with the engine O/H shop indicates to me that they suspect a compression leak into a coolant passage which is pressurizing part of the head or block therefore, preventing proper coolant circulation. It makes sense to me that if that was happening, eventually that area would get very hot and eventually blow, much like Old Faithful at Yellowstone.

Thanks for all of your suggestions. You folks are like most Chevy owners...GREAT. If you think of anything else please let me know and I will pass it to Mark.

Bob D.

I am sure that it has been checked but if the timing is too retarded then the engine/cooling system will overheat. Just trying to think of anything that could cause the problem.

Use a CO2 tester to see if there is exhaust blowing into the coolant. If Mark has that much experiance I am sure he has one. If not you can purchase one at NAPA.
You remove the radiator cap and place it over the opening....that simple to use.

If they installed hardened seats there may also be a leak around one of the seats.

All,
They did install hardened seats. I told Bev that it is possible that may be the problem if the machining got too energetic.

Hope it is that simple. Having bad dreams about the block. All we can do is wait and see.

Still open to comments.
Thanks,
Bob D.

So, Mark, the garage mechanic, does not do the rebuilding? Does he sublet the rebuilding to another mechanic?

Bob

Its also not too unusual to have a cracked head on htis model. Seldom a block problem.
Never add water to the radiator when the engine is hot and when water is added have the engine running. More heads have been cracked by addig cold water to a hot engine.
Keep us posted.

I will keep you up dated. Right now, Mark is getting rid of some backlog work so he can put Bluebird into a bay. He will not store it outside so it takes up space for some time every time he has to do something on it.

I guess bobg's description of Mark's operation is correct. He does not have time or equipment to do major O/H's like auto trannys and engines or radiators so he uses machine shops that are fully equipped and who back up their work. He certainly cannot afford to get hung out to dry by shyster operations. It is only him and now his son (out of the service) in a 4 bay garage.

Bob D.

Gene, you are right on about adding water to a hot engine.

Bob, do you know if the head was magnafluxed or not. I can't imaging a competent machine shop not doing so.

One time my machine shop told me that I has a "boat anchor." His exact words. I told him "No way." He said "way." I told him that it had looked OK to me when I brought it in there. He then showed me the magnafluxed head and sure enough right around the valve seats it showed hairline cracks at several of them. "Boat Anchor." Fortunately, I had a NOS one at home. I also had a NOS head.

Rignt now, I'm think the problem is in the radiator rather than the block. But it would be easy for me to be wrong. Still, there's a high perecentage that It's one or the other.

Did you perform the simple tests on the engine that Gene and I suggested? And did you check the radiator as suggested?
If it's invasion of the engine you're worried about then the tester wouldn't be invasive, in any way.

Best of luck on fixing the problem,
Charlie

Recore the radiator. Even though my old radiator checked out fine, no leaks etc., that's what I had to do after the engine rebuild. The car ran hot like yours.

One of the Wisconsin Regions members with a 1947 had an overheating problem. Engine was rebuilt. Had the radiator boiled out. No improvement. Flow was said to be OK. Found a NOS genuine Chevrolet radiator and problem was solved.

The following is NOT the problem but derserves some thought. The 1952 radiators were "decontented" as far as brass is concerned due to the Korean war. If I were to look for a new or different radiator I would find one for a 1953 or 1954. They had better cooling for the more powerful engines and are a direct bolt-in. They were also sold as the replacement for 1949 and up.

I forgot to mention the engine is also a 235, 1954 PG.

A friend of mine works in a restoration shop and ran into a similar problem. He rebuilt the engine on a 1930 Buick, the radiator was sent out for cleaning by a shop they had used for years, but when he ran the engine it would overheat in a few minutes. To check the radiator he ran the engine and when it began to overheat he sprayed the radiator with cold water from a garden hose. Instantly the temp dropped. The radiator was then sent to a different shop and after cleaning the flow was increased by 50 %. Perhaps using this method would help to determine if the radiator is the culprit with very little time or effort.

Hi again,
Sorry I have been silent. We have been out Scamping in the "wilds" of Northeastern Nevada.

I see a few people have zeroed in in the radiator. Thanks for your input Charlie, Dean50, and steve6.

The radiator seems to be cooling fine....warm water in the top and cool water out the bottom.

We drove the car for 650 miles after the overhaul with absolutely no cooling problems. This problem came on all at once after a short "cruise" down main street. The steam comes with a rush and a roar after shut down even if we do not actually take the car out of the driveway. (Many times with the temp gauge in the middle or slightly below middle at the time of shut down.) Naturally, if we drive it long enough, the temp gauge does show hot. When it shows hot, the gauge goes up dramatically fast from the middle line.

I am betting that they find a cooling passage plugged somehow or a hole or crack (possibly from the machining of the valve seats??) has developed what is creating a hot spot somewhere that is suddenly getting a shot of water that becomes immediately superheated and blasts out of the engine into the radiator.

I do not know if the O/H shop magnafluxed the engine or not. I would certainly hope so...poor practice to not do so....

Thanks to all.
Bob (still a waitin' in limbo) D.

You may have blown a head gasket or cracked the head.

Do a compression check to see if the head gasket is blown between cylinders.

Fill the radiator to full, start the engine and watch for bubbles in the top of the water. Could indicate a cracked head.

You may have to remove the head and have it magnafluxed and pressure tested.

Hi Ray,
Did you go to Charma?

Cal is getting close to having Matilda's engine finished.

We are down to the last step you suggested in your last post. Radiator checked, head gasket changed even tho compression check was OK.

Just waiting for Mark to get out from under his summer backlog of shop work.

Bob D.

Did you go to Charma?

I miss the point of this question.

I will be back down your way shortly for the early 6 meet at Mended.

Will bring the 33 Eagle.

I almost lost the engine in the 28 Touring at the NW Meet in Silverdale WA. Water pump packing took a walk and lost all my water. Had to drive almost a mile up and down hills before I could find a place to get off the road. The touring went back to home base on the trouble truck. When I got home all I had to do was change all plug wires, change oil and work on the water pump. It will be going into storage for the remainder of the year and I will use other cars for the rest of the tours.

Ray,
Sorry, I meant the Chama, NM tour. I was not sure if you planned on joining that one.

I am sure glad nothing major happened to your beautiful 28 touring.

Have fun at Minden. That is one tour that REALLY filled up fast. Should be a good one.
Bob D.

Bob,
Missed y'all on the Chama Tour. Had a great time. Took the old '51 and despite growling water pump it made all the miles. Guess the touring gods were on my side.

Hopefully next year will be better. To have problems with two cars is way too much bad luck.