My STOCK answer on over heating problems: (beside changing a radiator or water pump)
If you got the tools or access to the kit........pressure check the system.
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T-stats can be checked w/ a thermometer and a pot of hot water………or just replace them……….they aren’t that expensive.
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While running and with the engine off, make a visual check of the hoses for a hole, check for leaks at the connections. If it passed the pressure test, you should be OK. But, still check for a, "too soft" hose, which may collapse.
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Replace radiator cap........IF, you can't remember when it was last done........or if it's been more than a couple years since it was last changed. If it passed the pressure test, you should be OK.
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Time for new anti-freeze………don’t forget to mix it right.
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Fan Clutch...............when cold (engine off) try spinning the fan....it should spin freely or with very little resistance. If it won't spin.....replace.
When hot (engine off) try spinning the fan........in some cases it will feel like it's, "locked up," or it will be like there is syrup/glue holding it back. Tougher to spin, than when it was cold. If so, It's OK. If, it spins like a top.....replace.
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The below elec. tests are the, "cheap test methods"........there are more sophisticated tests with values, that can be run.
Test for the dash thermo gauge................disconnect the wire from the temp sender unit.........KOEO...........ground that wire.........it will peg the gauge on the hot side............disconnect from ground and it will return.
Sender unit.........if you suspect it..........replace, replacement is cheap.
Aloha, Mark