Ford quietly redesigned the thermostat in 2022...replace it

[wakeboarder]

Mine is a 2019. Later years may be different. It was in the IPC. I used the advanced method, but I think it can now be done with the drop down menus.

 

[Mr Big]

Can you tell me or show a photo of where? I can’t find the option.

If I remember correctly, it's under IPC non as built section.

 

[bocabimmer]

So just to confirm I’ve read 9 pages correctly: there’s no actual reason to replace your t-stat if your temps aren’t spiking above the designed opening temp? The redesigned t-stat is more about not sticking closed than establishing a lower operating temperature for the transmission?

 

[Dice Roll]

So just to confirm I’ve read 9 pages correctly: there’s no actual reason to replace your t-stat if your temps aren’t spiking above the designed opening temp? The redesigned t-stat is more about not sticking closed than establishing a lower operating temperature for the transmission?

I’m now past a month with the new stat. It’s seen 195 on the trans once in that time. Before it was 205 constantly. Usually now it’s 180-190. That’s reason enough to change it.

 

[bocabimmer]

Is that running the RT1252 or the RT1250? Both are listed as 190 degree on Rock Auto.

 

[Hellwig]

Is that running the RT1252 or the RT1250? Both are listed as 190 degree on Rock Auto.

It sounds like RT1258, which opens at 180F

 

[Mr Big]

I just read from Ford Motor Company that lowering the thermostat below the vehicle's specs, as well as using a non-Ford part can cause the following issues. The lower the thermostat temp, the more wear it puts on the engine, as well as more gas consumption. If a non-OEM Ford part is used, it may void the warrant.

Some food for thought:
Coolant temperature below the OEM specification is not recommended.

• Most engine wear occurs when the engine is cold, as bearings, rings, and other parts are not fully expanded. These loose parts move around and wear faster.
• Optimum fuel burn occurs at higher temperatures. Lower temps can cause some fuel not to burn all the way. This will reduce power and fuel economy.
• OEM computers ignore the O2 sensor until the engine reaches operating temperature. No “self-tuning” occurs at lower temperatures. Long warm-up times will cause the “Check Engine” light to come on.

As I previously stated, I don't seem to have high temps compared to others, and I am in Florida. But my vehicle is equipped with the HD tow package which includes a Heavy-duty auxiliary transmission oil cooler and Heavy-duty radiator. And since I don't tow, my temps stay cooler.

 

[Hellwig]

I just read from Ford Motor Company that lowering the thermostat below the vehicle's specs, as well as using a non-Ford part can cause the following issues. The lower the thermostat temp, the more wear it puts on the engine, as well as more gas consumption. If a non-OEM Ford part is used, it may void the warrant.

Some food for thought:
Coolant temperature below the OEM specification is not recommended.

• Most engine wear occurs when the engine is cold, as bearings, rings, and other parts are not fully expanded. These loose parts move around and wear faster.
• Optimum fuel burn occurs at higher temperatures. Lower temps can cause some fuel not to burn all the way. This will reduce power and fuel economy.
• OEM computers ignore the O2 sensor until the engine reaches operating temperature. No “self-tuning” occurs at lower temperatures. Long warm-up times will cause the “Check Engine” light to come on.

As I previously stated, I don't seem to have high temps compared to others, and I am in Florida. But my vehicle is equipped with the HD tow package which includes a Heavy-duty auxiliary transmission oil cooler and Heavy-duty radiator. And since I don't tow, my temps stay cooler.

Would you please let me know what are the transmission temps during cruising, idling and towing? My vehicle has HD two pkg too, and its tranny temps fluctuate from 190F to 200F when cruising, 195F to 205F when idling, and 195F to 215F when towing my 4300 lbs trailer.

 

[bocabimmer]

I just read from Ford Motor Company that lowering the thermostat below the vehicle's specs, as well as using a non-Ford part can cause the following issues. The lower the thermostat temp, the more wear it puts on the engine, as well as more gas consumption. If a non-OEM Ford part is used, it may void the warrant.

Some food for thought:
Coolant temperature below the OEM specification is not recommended.

• Most engine wear occurs when the engine is cold, as bearings, rings, and other parts are not fully expanded. These loose parts move around and wear faster.
• Optimum fuel burn occurs at higher temperatures. Lower temps can cause some fuel not to burn all the way. This will reduce power and fuel economy.
• OEM computers ignore the O2 sensor until the engine reaches operating temperature. No “self-tuning” occurs at lower temperatures. Long warm-up times will cause the “Check Engine” light to come on.

As I previously stated, I don't seem to have high temps compared to others, and I am in Florida. But my vehicle is equipped with the HD tow package which includes a Heavy-duty auxiliary transmission oil cooler and Heavy-duty radiator. And since I don't tow, my temps stay cooler.

See, this is what I’ve also kind of been wondering. The prevailing attitude is that lower temps are better. Is that necessarily true?

My non-towing transmission temps range from 195-205 depending on my driving.

 

[Hellwig]

See, this is what I’ve also kind of been wondering. The prevailing attitude is that lower temps are better. Is that necessarily true?

My non-towing transmission temps range from 195-205 depending on my driving.

The root of the problem is Ford doesn't adopt independent air cooler to cool down transmission oil. Expedition's transmission oil temp is bonded with engine coolant temp.