[xtremefreerider]

Last week truck warmed up, after a thinking it through and consulting a few mechanics we decided fan-clutch was gone.....well we were wrong (the fan clutch did have 210k on it so I keep the new one)....I am thinking thermostat but is there any way to be sure its not the water pump. I have one day next week to work on it and its a 1.5hr round trip to town so I need to get the right parts the first time.
The pump and t-stat have about 10k on them. The t-stat is a carquest brand, I have heard that only IH/Ford parts work right in these.

Thanks for the help.

 

[NorCalPR]

I too had overheating problems. If going downhill, it would run in about the middle. When on flat ground on the freeway, it would go all the way to the L on normal. Towing, forget about it.

I flushed the coolant, a bit better (Also using the additive). Changed the fan clutch because it was faulty, it was a bit better. Changed the thermostat and it runs really cold!

You are correct though, the Ford thermostats are pretty much the only ones that work correctly, and I think it has something to do with the bypass.


What are your symptoms? Mine was stuck slightly open. It would take forever to warm up. My sign on this was the fluid was running around in the radiator when the motor was cold.


Way I look at it, a thermostat is cheap. You should ahve the Ford T-Stat in there anyways. If not (And you are running good coolant with the additive) change out the pump.

 

[xtremefreerider]

I have yet to check the t-stat. It warms up like normal but keeps on going up. I have an autometer temp gauge so I get a slightly more accurate reading than stock. I ordered a t-stat but the parts guy was convinced that it didn't make a difference if it was Ford or a good aftermarket brand. The water has less than 12k on it. There doesn't seem to be in water moving from the t-stat to the radiator...but its kind hard to tell as of now. I will try again on tuesday with the t-stat. Thanks for the help.

 

[arthurgoboom]

As I have read on here, aftermarket thermostats have a bypass in them which interferes with the operation of this engine, since it has a check ball in the thermostat housing that is supposed to be the bypass instead. Ford/IH 'stat has no internal bypass and is the only way to go in these according to the gospel.

I have heard rumors on various engines of a stuck open thermostat or no thermostat installed causing an overheating problem because the coolant is moving so fast through the radiator that it doesn't have time to cool it any. Perhaps you are experiencing this?