Packard Forum Index » Post-War (1946-54)

Still chasing the my PACKARD wants to overheat issue. Have gone down the list of recommendations and I am now thinking about removing the five freeze plugs and scraping out any build up. I need to determine the which size freeze plug that is correct for the 1948 288 engine. Would like to have everything on hand before I start this repair. I must be dense because I cannot find the information in literature and manuals. Where can copper freeze plugs be purchased?
What I have checked so far.

1. Timing dead on
2. Water pump
3. Fan Belt
4. Radiator was serviced and cleaned two leaks fixed
5. Thermostat installed
6. Correct radiator cap installed
7. Water distribution tube checked and it is clear no build up
8. Head gasket all cylinder compression are in range

Your core or welch (freeze-out plugs is really a misnomer) aren't copper, they are plated steel, of the cup type (not the disc type) and should be easily found at a good auto parts store. Sorry I don't recall the size but we picked them up last year for a 288 engine off the shelf at a local store.

BTW, if your indications of overheating are based on the temperature gauge in the car, have you checked it against a good quality thermometer?

EDIT - the 48-54 parts book lists the expansion plug as 2 inches.

Thanks Owen my local part store doesn't list my car. Wanted to get what I needed before beginning.

This might be a stupid suggestion, but did you check the antifreeze/water ratio? I had a car that overheated because someone put in too much antifreeze compared to the water. I don't know if this would be true on a straight eight though. The car that was overheating was a 4 cyl.

Just had a thought. Sounds like you have checked everything that could cause the problem. My question is "what makes you think the engine is overheating"? Does it boil over? If you top it off and then run it hot then shut it off it's normal for some water to go out the overflow. The radiator will not stay full to the top. It will run maybe an inch or two below completely full. As long as there is water over the tops of the tubes it is probably OK. On hot days my gauge will point to the "P" in the word temp but has never boiled over. With a 7 pound cap the water temp is probably not much over 212 degrees. Maybe 225/230. My thought is maybe you don't have a problem at all.

If it's not boiling over when you are running it then it's not overheating.

Good point may not have a problem it seems the more it is run the temp gauge does not try to peg on hot. May just run it a bit longer. Stopped by the local garage to use their lift and have new project to work on. The transmission and differential are leaking around the drive shaft. It is fun to own old cars. Heard there is an old packard in a field in Apex, NC may have to drive by to check it out. Thanks again to everyone for your help.

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Any new information on you problem? Have you been able to drive the car without it boiling over. What are your conclusions so far?

If the Packard in Apex is the one I remember, its not in a field but in a grove of trees (pines). Its a pretty complete 1953 Clipper sedan, I think.