Technical Water boiling

Hello everybody, I'v been ownin' a 1954 Chevy Bel-Air, over here in Italy for almost 40 years now.
Lately water/liquid started to boil. I checked the thermostat, but it was ok. I even tried without thermistat, but water kepr boling.
So, I was enough sure somethin' happened to the head gasket. I went to my local car repair shop: they checked the head..and the mechanical test said the head was ok. Anyway they rectified it and they're goin' to put a new gasket on, of course.
Now, do you think this boiling is caused by a failing water pump ? Or radiator ?...
Any idea ? I never had water boling problems at all. Thanks so much for your help. Alberto

 

By boiling do you mean it’s overflowing? What does the temperature gauge read?

could be as simple as a the radiator cap

when it’s hot feel different parts of the radiator, are there cold spots?

 

Yes, it's overflowing. Unluckily my temperature gaude doesn't work....so I don't know.
Now the radiator is apart...

 

I think I am goin' to redone the radiator core...what do you think about it ?

 

Did the shop remove the head? I don’t know of another way to check it for cracks other than removing it.

Do you have the car at home now? And have you removed the radiator? I ***ume that’s what you mean by “have the radiator apart”.

And it still boiled over with the thermostat removed? Okay, put the radiator back in, keep the thermostat out, fill with water and fire it up and let it run with the radiator cap off, see if any bubbles are forming through the fill hole.

Are any of the spark plugs noticeably cleaner that the others? If so, this would indicate that cylinder is getting water/coolant in it and “steam cleaning” the spark plugs

 

Yes, the head and radiator were (are) removed.
I am goin to check if the radiator is ok.
Will check the spark plugs.
Thanks for the advice.

 

Long as the radiator is out, pull the pump & make sure the impeller hasn't started to spin on the shaft. It happened to me once with a ''rebuilt" pump ...

 

While you have the radiator out take it to a radiator shop and have it flushed out to make sure it isn't clogged up. HRP

 

Do you have easy access to any of the core plugs in the side of the engine block? Removing a plug may tell you if the coolant p***ages in the block are plugged with rust or scale. Also check your ignition timing. If it's retarded too far it will make the engine temperature increase. Getting a working temp. gauge would also be a big help for troubleshooting.

 

Ok..thanks for the advice.

 

Yes, thanks. I just planned this. Thanks.

 

For that matter, is the belt properly tensioned?

 

Good golly, miss molly! Get the temperature gauge working! If it had been working you would have seen the coolant temperatures rising over time. The radiator is probably at least partially plugged. Since it is off, have it rodded out. Or a new core. Afterv40 years [ good for you ] a new one would not hurt.

Ben

 

Thanks. I am goin to check everythin I can. Thanks

 

Yes, I would say it is.

 

I know..you're right..
I am goin to have it working.

 

I bought a car once really cheap, because the owner said it overheated and would boil over. I put a new radiator cap on it and never had an issue after that.