1993 Mazda b2200 over heating

check to see if radiator fan(s) coming on properly

[quote:153dd6d755="waynesanders333"]Engine Cooling problem
1993 Mazda b2200 4 cyl Two Wheel Drive Manual 155000 miles

I have changed the waterpump, thermostat,hoses andput new coolant in the truck but it still heats up . No oil in the coolant either. I can turn the heater on and it cools right down . what could it be?[/quote:153dd6d755]

you might need to to have the radiator flushed...

Radiators do get plugged which contribute to overheating problems because water will not cool and flow. You check this by draining a bit of water/coolant and look for standing water in the radiator tubes. It should not remain in the tubes if you lower the water level. If water in the tubes you'll want to take it out and have it boiled and pressure flushed. You can get enough pressure from a garden hose flush. Also check to see if the radiator fins are coroded if made from copper. They need to be in top shape to dissapate heat. If bad you are better off replacing the radiator than investing in a repair or flush.