When driving at any speed, runs normal temp. Begins to heat up at idle. This shows thermostat is good. Radiator is 1 year old and runs 50/50 mix. Replaced clutch fan today. See no white in oil or dark in antifreeze. Seems no head gasket due to this. Thinking temp sensor ok due to dash reading normal when driving and reading high at idle. Possible radiator cap? By the way, I find no leaks. And I have good air flow now thru radiator due to new fan clutch. I'm stumped!!!
My car has 223000 miles.
My car has an automatic transmission.
Inspect and verify that there is no plastic bag/trash on front of condenser or up between the radiator and condenser. Plastic ductwork around the fan are all present and intact. You should also consider whether the fan clutch an OEM or aftermarket part.
With the engine fully warmed up/hot, shut it off and attempt to turn the fan by hand. You should feel significant resistance if the fan clutch is providing a proper viscous connection.
Verify actual temps using an infrared non-contact temp gun at the thermostat housing. Pressure test the cooling system and cap to verify no leaks, external or internal. The levels in radiator and overflow tank should be stable, staying the same, and requiring no addition of fluid. Does that water pump also have 223,000 miles? Replace that radiator cap for cheap insurance - as those can wear out after time. If you need help having this looked at, a technician from YourMechanic can come to your home or office to diagnose your overheating issue and make the correct repairs.
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