Help Help! Thermostat Maybe Going?!?

[4x4.Ranger]

my temp gauge in my dash builds to the lowest normal running temp then it goes to cold again i am unsure of how hot of a thermostat i need and i am going in to the city tomorrow anyway so i could get parts also so any advice would sure help!

 

[4x4.Ranger]

o and its a 94 ford ranger 4.0L v6

 

[Mutant Pony]

Make sure the new thermostat has one of those little check valves in it. Get the one that is recomended, 195deg I believe. If you can't get a thermostat with the little check valve in it you can drill a tiny hole (1/16th") and position the hole at the top. A little trapped air can destroy a thermostat, the hole eliminates the problem.

 

[MAKG]

The behavior just described is consistent with AIR in the cooling system.

Stock is 195 deg. But the thermostat will never open CORRECTLY if there is no coolant against it.

 

[grey ghost]

The behavior just described is consistent with AIR in the cooling system.

Stock is 195 deg. But the thermostat will never open CORRECTLY if there is no coolant against it.

+1

 

[4x4.Ranger]

awsome thanks for the help everyyone!
Ryan

 

[westonoto]

Interesting. My 99 3.0L 4wd just developed a problem that sounds similar. I figured thermostat and changed it, but no luck. Seemingly randomly, I'll run the truck 20 or more miles with no problem at all. Then on the next cold start and run, I'll make it a couple miles then no heat at all and temp gauge bottoms out. Invariably, the cap blows off the overflow tank and spews antifreeze all over the place. But the kicker is that the radiator is empty. Seems to be overfilling the overflow tank while emptying the radiator. Caught it early the last time and noticed that the upper radiator hose was nearly collapsed from the vacuum, yet the overflow was overflowing. It happens more on cold (20-30f) mornings or nights.

Any ideas?

Thanks

 

[scotty810]

Interesting. My 99 3.0L 4wd just developed a problem that sounds similar. I figured thermostat and changed it, but no luck. Seemingly randomly, I'll run the truck 20 or more miles with no problem at all. Then on the next cold start and run, I'll make it a couple miles then no heat at all and temp gauge bottoms out. Invariably, the cap blows off the overflow tank and spews antifreeze all over the place. But the kicker is that the radiator is empty. Seems to be overfilling the overflow tank while emptying the radiator. Caught it early the last time and noticed that the upper radiator hose was nearly collapsed from the vacuum, yet the overflow was overflowing. It happens more on cold (20-30f) mornings or nights.

Any ideas?

Thanks

This is EXACTLY what mine is doing. Ever figure it out?

 

[steelheadboy]

Same problem with mine too!!! help!!!!!! im pulling my hair out trying to figure it out!!!!!!