From the surface this looks like a normal radiator from a 1997 crown victoria police interceptor





But the car randomly decides to run real warm sometimes. But other times, the coolant guage gives normal readings. The waterpump and mechanical radiator fan are new and have less than 1,000 miles on them. So the radiator is a likely culprit.



After cutting the radiator apart using a sawzall







Here's the problem. Some "car repair expert" poured copious quantities of some sort of stop leak product in the cooling system. The stop leak likely slowed the intake manifold leak that was referenced in the vehicle's repair history, but it also adversly affected the heat transfer of the radiator too.





The metal tube in the radiator end cap is used to transfer heat from the transmission oil into the engine coolant



The tranny cooler lines didn't want to come off of the radiator easily and the fittings at the radiator side "spun" and broke off the tranny cooler tube inside the end cap.

Attempting to use a radiator with a broken off tranny cooler would have resulted in engine antifreeze mixing with the tranny fluid. So 1997 & earlier crown vic owners looking to "save themselves a buck" by purchasing a used junkyard radiator could end up costing themselves thousands of dollars in transmission rebuild costs.