As for setting codes, not necessary. when I did a search for mystery overheating problems several recommended checking the cats. Just 1 to 2 psig can cause overheating at cursing speeds. There should be no back pressure. I also check the EGR valve. If not opening it can cause overheating issues.
Yes the water pump was replaced with a gates that has a metal impeller. Not a fan of metal plastic interfaces when it comes to thermal cycling. The original with the plastic impeller was in good condition. Was concerned that the metal shaft to plastic impeller may be slipping. The replacement made no difference.
I could be mistaken, but if the converters were defective enough to cause the engine to
overheat, I would be surprised if a fault code wasn’t set.
A defective
catalytic converter can impede the natural flow of exhaust emissions exiting a car's engine, thereby increasing the amount of back pressure within the car's engine, which can lead to
overheating. As the exhaust pressure builds up within a car's engine, the natural combustion that occurs is compromised. In an engine that is operating normally, combustion happens at precise times and in correct amounts. A faulty
catalytic converter, which can disrupt the normal combustion properties of an engine, can force the engine to work harder in order to emit the burned exhaust gases out of the tailpipe. This raises the operating temperature of an engine, and if left untreated, can definitely cause a car's engine to
overheat.
When I worked at the dealership we charged 1 hour labor to replace both converters, plus 1/2 hour converter diagnosis. 4W4Z5F250AA is the converter
part number, but contact the dealer for most current
part number and price information.
Since this is an expensive repair, I would check with whoever diagnosed the converters as a cause of the
engine overheating and see if they will guarantee the diagnosis.
Let us know if replacing the converters corrected your
overheating concern.
doug7740
1955 Thunderbird Blue
