2021 Powerboost High Transmission Temp while on interstate

[Big Dog Daddy]

Just looking for additional info. What was the ambient air temp during your trip. How long was your trip, and how fast were you going?

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[EricR]

The 10r80 has a liquid/liquid heat exchanger.
No air flow involved.

Is this for all 10r80s or just with the Powerboost?

 

[Gros Ventre]

The 10r80 has a liquid/liquid heat exchanger.
No air flow involved.

OK, a restriction in the cooler either in the oil side or the coolant side... The simplest thing could be some junk got in the coolant system and lodged in that side.

 

[Waynejohnson30705]

Just looking for additional info. What was the ambient air temp during your trip. How long was your trip, and how fast were you going?

It was 86 yesterday, I had been on road for about 30 miles at around 74 mph.

 

[Snakebitten]

Is this for all 10r80s or just with the Powerboost?

All of them.
Although Ford did relocate the heat exchanger on the Gen14. Since 2017 it was mounted below and in front of the transmission pan. Right out in the open from underneath.

Orange in this picture:
(you can see it nestled under the bell housing)

Now it's tucked up on one side of the transmission. I believe the passenger side?

 

[Gros Ventre]

Does this Hi temp only occur at interstate speeds? If not when does it begin? Have you checked to see if there's a load dependency? ie you were low load initially, how about hi load and lower speed?

 

[Waynejohnson30705]

It does it faster on interstate. It's never been loaded since I had the truck. This is the first time it actually told what was going on. It done last week and gave no indication of temp, and when I went and looked it required no service.

 

[Gros Ventre]

It does it faster on interstate. It's never been loaded since I had the truck. This is the first time it actually told what was going on. It done last week and gave no indication of temp, and when I went and looked it required no service.

Doesn't add up.. recall my experience with a missing rubber o-ring/gasket and refusal to go into gear until warmed up. If I was a betting man... I think you have either something like this inside the transmission or some crud has gotten into the water side of the cooler restricting flow. In any event the dealer owes you some warranty work.

 

[Waynejohnson30705]

Doesn't add up.. recall my experience with a missing rubber o-ring/gasket and refusal to go into gear until warmed up. If I was a betting man... I think you have either something like this inside the transmission or some crud has gotten into the water side of the cooler restricting flow. In any event the dealer owes you some warranty work.

They are picking it up in the morning and supplied me a rental. I'll post what it was when they let me know. Thanks again.

 

[Gros Ventre]

They are picking it up in the morning and supplied me a rental. I'll post what it was when they let me know. Thanks again.

 

[Calson]

The flash point for transmission fluid is at least 355 degrees and with some ATF it is 487 degrees. The purpose of tow/haul mode is to minimize heat buildup in the fluid.

 

[imnuts]

About 2 weeks ago I drove from NJ to MA. About 2-3 hrs in I was going through CT, there was one point on I84 with a long uphill grade. This was after several other rolling hills. I looked down and the transmission was at 210-215, coolant was running around 195-200. Shortly after that, there was a longer downhill section of the highway and more flat, light engine load stretch and the trans came back down to 195-200 to match the coolant. This was basically unloaded at 85-90 air temps. Not what the OP saw, but even light loads can get the transmission to warm up.

 

[Savannah Power]

My 2021 Powerboost trans temp got high enough when towing a U-haul that it gave the "Get off road " message. I had trans temp gauge set to boost so didn't notice temp climbing, gotta watch that one.
Took to dealer, a month in the shop just to get it checked. Gave it back to me with 2 qts ATF added.
Next time I trailered, same thing. This round they changed out the heat exchanger which has a solenoid-operated bypass valve. Apparently these stick in the open position so the ATF bypasses the heat exchanger, problem seems resolved.
Thing is, there is no way for them to test the exchanger bypass, they just have to swap it out based on overheat conditions. Mine was fixed under 60K drivetrain warranty at 59K miles.

 

[Waynejohnson30705]

My 2021 Powerboost trans temp got high enough when towing a U-haul that it gave the "Get off road " message. I had trans temp gauge set to boost so didn't notice temp climbing, gotta watch that one.
Took to dealer, a month in the shop just to get it checked. Gave it back to me with 2 qts ATF added.
Next time I trailered, same thing. This round they changed out the heat exchanger which has a solenoid-operated bypass valve. Apparently these stick in the open position so the ATF bypasses the heat exchanger, problem seems resolved.
Thing is, there is no way for them to test the exchanger bypass, they just have to swap it out based on overheat conditions. Mine was fixed under 60K drivetrain warranty at 59K miles.

I'll mention this to them. It's going today.

 

[Snakebitten]

Great post @Savannah Power

That makes a lot of sense. Certainly fits the symptoms.

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