P12 Overheats...but Only With The Hood On...long Post

[55 Fargo]

Glad it all worked out, and 170-180 around town in good hot weather seems okay to me. On the highway, and going fast =high RPM=hotter engine temps.

[Chuck51631]

I will give you my two cents. I had a similar problem with my 55 Plymouth. The car ran fine around town and at idle. When I took it out  on the parkway for a long run the temperature gauge would go towards hot. When I got off the parkway and drove at slower speeds the temperature  would drop.  I did all the flushing, looked for collapsed hoses changes the radiator cap etc.. Finally I pulled the radiator brought it to the shop to find it had a restricted flow along with a few weak spots that would eventually become leaks. I had it re-cored put it back in the car and have not had a problem since.