I have a 1972 pre L that I went through a few years ago after being in storage for 45 or so years. I had to remove the fuel tank so I went through the engine while it was out. Everything replaced in the cooling system including a " GT5" radiator with one pusher and one puller fan. The first 2 years of driving the temperature never went over 205 on the hottest So Florida day in traffic after a 250+ mile trip . Now all of a sudden I hit 222 degrees at the hottest part of the day around 94 degrees outside. On the way home it was in the low-mid 80's and the car stayed at 205-208 max. ( I'm running a mechanical gauge in addition to my factory one). The car has never boiled or puked any coolant. Does anyone have any suggestions? I am going to drain the coolant and replace the thermostat to begin with. Next would be to have the radiator cleaned although everything is new in the cooling system. The crazy thing is this car never ran hot before and just started this . We have been having record heat but 94 degrees isn't too crazy . Thanks in advance with any suggestions. Ian
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Please tell us about the cooling pipes underneath the car.
were they replaced, removed and cleaned, left in place with no inspection?
Have you confirmed both fans are still operating correctly?
Seems you have a handle on the problem. The most likely culprits are air in the system or a thermostat that’s not working as it should anymore. Try filling the cooling system with a vacuum filling device. Also, make sure you get a real 351C thermostat. I know tmeyer sells them.
So yes the cooling pipes were replaced and both fans are working. Yes I have the correct thermostat and the "washer/restrictor" in line.
I concur with David that the problem could be air in the system. A healthy cooling system in a Pantera can appear problematic if all of the air is not purged. There are several ways to purge air from the system.
If there is a vent line and undercar vent tube from the top of the radiator check it is not blocked. All the sediment drops into the lowest point and that skinny little tube will get blocked. Then no venting and a problem.
Problem found. When I took off the engine cover i found the water pump belt was loose. Ill test drive it tomorrow but i'm pretty certain this was the problem. Thanks for all the input.
Strange you didn't hear anything.
That belt drives the alternator as well. Did you have any charging problems or was the battery low?
Fingers crossed that the fix is that simple
As a precaution when the car is cold take the radiator cap off and look inside the swirl tank with a flashlight. The water should be at the very top. If not then air is in the system and/or there is some other leak.
Also, make sure there is water in the overflow tank.
With the cooling system cold, the swirl tank should be completely full and the overflow tank should be about half full.