I recently purchased a 1969 xr-7 cougar with a 428 CJ . I have been working on cooling issuesI reviewed the radiator size the clutch fan and the fan blades all seem normal for car. I removed the thermostat housing and there was not one. I installed a recommended 190 new thermostat. I proceeded with flushing the radiator and the motor. I drove the car today in 80 degree day and it was spewing the fluid out the radiator cap. That being said it was not that hot according to the normal in dash gauge.The radiator cap is a motorcraft RS-512A 13# Looking for better results for a fix. Any thoughts?
Time to take some measurements with an infrared thermometer to see what is really going on. With the thermostat open, you should see about a 30 degree drop from top radiator hose to bottom, and see the coolant flowing through the radiator with the cap off. And then measure temp at the temp sender to see how hot the engine is actually getting. 50/50 coolant mix at 13 psi shouldn’t boil over until 250 degrees or so.
You could have a plugged radiator, gunk in the engine coolant passages, water pump impeller rusting apart, bad fan clutch, or some combo of these.
Overfilling? Fluid should just cover tubes when cold.
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Pressure test the cap.
OK I can check with infrared thermometer. Looks like the motor was rebuild in the 2013 era. Runs well and feels powerful. Could any emission items that it has cause the issues. Thanks for the input.
I checked the manual and kept it down 3/4 from top of bottom of cap. So i could lower it a bit since now i see none in radiator.
I notices on the 68 GTE has a 18# cap and all other items are the same Radiator, clutch fan ,fan blades, fan guard. I put that one on it temporarily to check it but have not taken out to try it.
Late ignition timing can cause overheating, but we don’t yet know if it really is overheating or not.