Fan clutch either works or doesn't, your call.
Use a flush (follow the instructions, I like Prestone Super). I've been known to drive a couple miles with the flush in there.
THEN, replace the thermostat (good preventive maintenance), but stay stock temp. Most AP stores offer several thermostats, go with the high dollar model (still cheap, unless those 4 bangers have something special about them - temp sensing?).
While the coolant is drained replace any "iffy" hoses.
Use the 5 year coolant, since you tend to neglect it (no offence intended). Leave the top hose at the radiator loose, so you can burp out the air when the thermostat opens (wear gloves). Don't fill the overflow reservoir until all the air is out and the radiator stays full when you goose the gas.
If you replace any hoses, I like to clean the nipple with sandpaper and coat each connection lightly with black RTV, so the new hose seals reliably. I've also used gasket sealer in the past, either works.
Dispose of old coolant properly, don't let your pets lick it.
2000 2.5 MO5D 4.10 one-wheel drive DD - gave to my older son
1990 STX 87 2.9 going in.....Junked it
2000 3.0 4WD M05D 4.10 S-cab Off-Road package with 235-75-15" tires, hotrod DD, lol