I have a 1998 Ranger with the 2.5L engine, and I've noticed that at idle and low speeds, the temperature gauge with go 3/4 to all the way up, and the AC will blow hot air. I was thinking of starting with the thermostat and flushing the radiator. Is there an easy way to check if the fan clutch or water pump is broken? Thanks.

 

Welcome to the forum

Won't be thermostat or radiator

AC blowing hot is odd

Most likely Fan clutch is bad

Next time engine is cold before starting open the hood and try to spin the fan blades
You should be able to move the fan but not spin it.
After engine is full warmed up, after a drive, open the hood and do the same test, it should NOT spin
If it does you need a fan clutch

Water pump can have the same symptom, impeller blades get worn down if coolant is not changed every 2 years, so at low RPMs it can not circulate coolant fast enough.

Check fan clutch first and replace it if bad, it it still get warm at idle then change water pump.


Bad Thermostat or bad radiator would cause overheating at speed, higher engine heat, so limited circulation thru thermostat or radiator

 

I agree with the above. My guess would be bad fan clutch. I have yet to see impeller blades wear down with a 50/50 mix and I never change coolant.