1954 Pontiac overheating straight 8

[002412]

It is overheating at both low and high speeds. Access covers and radiator shroud were removed to see if that would solve the problem, it helped a little. Radiator was purged and cleaned and the water tube was cleaned out. Does anyone know anything else that I should try?

[Bodyworx]

You should have a small Pet Cock on the side of your motor towards the rear of the motor on the drivers side to drain the actual block. Try to get that open and see if anything comes out. Mine didnt because it was blocked so i took a small piece of wire to unplug it. if that was blocked that almost assures that there is other gook in there probably blocking everything up.

Do you have any coolant movement when the car is running with the cap off ( Warmed Up )? You will probably not see a flow like the newer car as the cooling systems were not as powerful back then. Do you have seperate Heater cores for your defrost and cabin heaters ? If so are they leaking? My Heater core under the drivers seat was leaking and i didnt even notice until i pulled it out. First off are you losing antifreeze at all ?

[stevep]

Disconnect the heater hose from the water pump and see if you ahve circulation. Did you try taking the thermostat out to see if anything changed?

[Larry]

I had a '54 that I did the same cleaning/purging to and it still overheated too. I had the radiator recored and the shop told me that the old one was almost completely closed up. They said no amount of cleaning will remove all the calicium and such that can narrow down the small tubes.

As suggested check for circulation first. If you are getting heat at the heater core(s), the water is circulating.

Remove the thermostst also, it isn't really needed anyway- forget whatever anyone might tell you about "holding the water back in the radiator longer to cool more". It's a wifestale.

If you run the car with the heater on and it runs cooler, then it is almost a sure bet that you neeed more cooling area (i.e. new rad core). Most Pontiac fans have horror stories of running in the middle of August with the heater on.