Packard Forum Index » V-8 (1955-56)

To some extent can I redirect the yopic to the original discussion? Everyone has always said overheating is a non starter with v8s. That said, mine overheats when crawling for long periods of time in very hot weather. On the highway, no problems.

Spposedly the radiator is fine and the block is not unduly problematic with regard to overheating.

What would happen if the thermostat was broken/defective, or the wrong temperature version? is that a possible issue given that it runs fine on the highway?

try setting the idle speed up a little faster to say 800 rpm. Very long periods of idleing or very slow operation such as parking lot manuevering can make just about any car overheat.
OR let me put it this way, if u started just about any car and let it just set and idle continuously in the hot summer time for say more than 3 hours i am fairly confident it would over heat and cause engine damage.

Since there is no problem at high speeds then the T'stat should be just fine.

From your own post in post #7 above u said:

"No, no fluid loss. FWIW it has a new radiator cap."

So there does not seem to be evidence of overheating to me.

What is the pressure rating of the cap???? Multiply 3 by the poundes of pressure rating listed on the cap and add that figure to 212. That will yield the boil point or fluid loss point.

IIRC someone said they had checked the factory dash gauge against a another thermometer or something. I don;t know what that test involved in terms of various long term and variable operating conditions (such as lites on or off etc.v).

BOTTOM LINE: ANY mfg'ers production electric dash gauges are UNreliable. When extensive diagnostics are required for potential or suspected problems then the production dash gauges (OF ANY CAR) is NOT reliable. And that's that.

Since the radiator is not puking anything out of it then i conclude thus far that there is NO overheating problem at all unless u're running an extremely stout or faulty rad cap.

Well he did say it was making it running rough...not necessarily an overheating problem, but if it's not getting too hot, then it shouldn't be affecting how it runs.

On bikes, i've seen crazy things look like they're heat related. Too thick of oil. Too thin of oil. Electrical contacts that only had trouble once the bike was hot. Maybe the engine is getting too hot but something minor going on kind of related like the carb soaking up too much motor heat over time?

I'd be more concerned about the transmission than the engine in an overheating situation. The trans oil only gets as much cooling as the radiator can give it.

No heat problems at all. But i cheated. I mounted a NEW Ford truck radiator bout at AAP for about $120. It fits just fine but is a little trickly to remove and replace due to it's size.
Packard v8
what ford radiator did you use? and does it have the trans cooler lines too ? did you reroute them add them in or just leave the trans going through the lower rad hose cooler from the factory?

Any pics showing the fit or part number for the radiator?