Random Overheating

[Haunted]

I have a 99 ford ranger 3.0 v6 flex fuel.
it runs like it should, except for sometimes it overheats.
sometimes on hot days or sometimes when were sitting at a light.
When it does, we usually turn on the heat and shift into neutral and rev the engine a little, that fixes it temporarily.

I've replaced the radiator, took out the thermostat and checked the hoses.

Although sometimes when it overheats, it spits water back into the reservoir causing it to overflow.

We're suspecting its the cooling fan clutch.
any other thought before we buy one and replace it? :rangertan:

 

[yavapaires]

Test the fan clutch first. Does the fan "roar" when you first start it in the morning, and then after thirty seconds to a minute the noise goes away? Is the fan stiff to turn in the mornings? Is the fan easy to turn after the engine is warmed up and shut off? Do you ever hear the fan roar when the engine overheats? These will tell you if the clutch is good or not.

 

[Haunted]

EDIT: i checked it this morning, and it seems that it does "roar" for about 20-30 seconds after a cold start.
After I'ts cooled down, you give the fan a good turn and it has about a 1/4 to a 1/2 of a rotation. and obviously a little more when its warmed up.

 

[yavapaires]

Well, your fan clutch seems to be working. Reinstall the thermostat. Try a 180 degree stat and see how it works. Be sure ALL the air is out of the system when you refill it. I find it helps to have the front end higher than the rear when filling the radiator, go slow when refilling. If none of this helps, then you have a problem internally, most likely a cracked head, or bad head gasket, in my opinion.