2021 Powerboost High Transmission Temp while on interstate

[Gros Ventre]

The one issue with the bypass valve is that at low load the heat losses from the transmission oil pan should be sufficient to keep temps around normal.

Sponsored

 

[Snakebitten]

 

[someday]

I'm towing my boat 100 miles in 90+ temps Thursday. Guess I better swap out the boost gauge for the trans temp gauge.

 

[Gros Ventre]

Aha

Aha... Dirty contacts, water-in-plug, broken wire, stuck valve... For all of the computer sophistication in these trucks, the fault comes down to the same old stuff... Still, is the low load heat output of the transmission so large as to be greater than what can be rejected through the transmission oil pan?

 

[Snakebitten]

Ford wants it to reach 205F
And it does at about a 20 mile normal empty truck drive.

According to the document, that external engine coolant valve is controlled by the pcm. I don't know if it opens to introduce engine coolant heat into the transmission coolant, or if it opens to let engine coolant remove heat from the transmission coolant.
I do know that when the tranny coolant is at 205F, that's a delta of 10-15F between the 2 liquids.

Also, there is an analog thermostat inside the 10r80 that doesn't allow coolant to flow between the "top" & "bottom" of the transmission until a certain temperature is reached. That's why when you drop the pan you will only get about half the total fluid out with gravity.

If you pull that thermostat out (delete), it's reported the transmission runs too cool and can't reach operating temps.

That makes me believe that the engine coolant is for both introducing AND removing heat from the transmission? And the pcm is measuring the delta and opening/closing the valve to maintain a equalization?

 

[Gros Ventre]

Ford wants it to reach 205F
And it does at about a 20 mile normal empty truck drive.

According to the document, that external engine coolant valve is controlled by the pcm. I don't know if it opens to introduce engine coolant heat into the transmission coolant, or if it opens to let engine coolant remove heat from the transmission coolant.
I do know that when the tranny coolant is at 205F, that's a delta of 10-15F between the 2 liquids.

Also, there is an analog thermostat inside the 10r80 that doesn't allow coolant to flow between the "top" & "bottom" of the transmission until a certain temperature is reached. That's why when you drop the pan you will only get about half the total fluid out with gravity.

If you pull that thermostat out (delete), it's reported the transmission runs too cool and can't reach operating temps.

That makes me believe that the engine coolant is for both introducing AND removing heat from the transmission? And the pcm is measuring the delta and opening/closing the valve to maintain a equalization?

Interesting. I've observed out in my neck of the woods that, in late spring thru summer and into early fall, the transmission gets up to temperature before the engine. In the winter that's reversed since the winters are so cold (below zero) in my parts.

 

[Snakebitten]

That's definitely not the case for me.

My commute is 23 miles one way. It's obviously summer here on the Texas coast.

ECT's are in the 180's by 6 miles.
Transmission temps don't reach 200 until about 18-20 miles.

 

[HammaMan]

That's definitely not the case for me.

My commute is 23 miles one way. It's obviously summer here on the Texas coast.

ECT's are in the 180's by 6 miles.
Transmission temps don't reach 200 until about 18-20 miles.

Where's the aux coolant pump that he PBs use?

 

[Snakebitten]

Do you mean the transmission auxiliary pump? (electric for when ICE is off?)

Right behind the valve body, nestled at the very rear. Blue in this picture:

 

[Kodiak]

I'm towing my boat 100 miles in 90+ temps Thursday. Guess I better swap out the boost gauge for the trans temp gauge.

Anyone that does any towing should have Trans Temp as one of the main gauges to monitor. Why this is not a front and center item on any/every truck as standard is a mystery to me.

 

[powerboatr]

mine is not a POWERBOOST
i would suspect the PB runs close to same same temps
but i took this pic this afternoon
these temps are within what i saw today on both high speed runs of 87 miles north, then return south 87 miles at or above 70 mph, with about 12 at 77

 

[Snakebitten]

That's indicative of my comment(s) regarding getting the transmission temp up to 205-215 isn't very easy to do quickly.

It can help to be in stop&go and slower speeds.
Dealership technicians, who need it at 205+ to follow service guidelines have the advantage of heating equipment and a couple of "off the record" techniques. I think one of them is to put it in drive with it blocked from moving? I guess you could have the e-brake engaged?

 

[powerboatr]

That's indicative of my comment(s) regarding getting the transmission temp up to 205-215 isn't very easy to do quickly.

It can help to be in stop&go and slower speeds.
Dealership technicians, who need it at 205+ to follow service guidelines have the advantage of heating equipment and a couple of "off the record" techniques. I think one of them is to put it in drive with it blocked from moving? I guess you could have the e-brake engaged?

i have seen it climb a bit over 200 in hot stop go traffic, but it drops pretty quick once your moving and it stop searching for gears
i have locked out gears in slower traffic to get it hold say 3rd when there are numerous red lights close together


i bet in DRIVE, blocked wheels and parking brake and about 1/2 throttle would speed up temps rise FAST
as well
i have seen water over 212 easy as pie idling with ac on in park. but a run of of about 1k rpm for a minute it cools back to 192 ish then starts that climb
i think the coolant just cant move around enough in idle to keep it cool as i desire it should be

 

[HammaMan]

That's indicative of my comment(s) regarding getting the transmission temp up to 205-215 isn't very easy to do quickly.

It can help to be in stop&go and slower speeds.
Dealership technicians, who need it at 205+ to follow service guidelines have the advantage of heating equipment and a couple of "off the record" techniques. I think one of them is to put it in drive with it blocked from moving? I guess you could have the e-brake engaged?

Putting it on the brakes in gear has always been a reliable method to heat trans fluid.

 

[oldschool]

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

Bruce,
Wonder if you could help me trying to check trans fluid level in my 21 pb. The Helm service info on CD mentions a diagnostic mode to keep the engine running while checking the level. It says to connect my diagnostic tool, then select the different shifter positions with engine running. Then place in park. Then push start button to enter accessory mode. Then press brake and accellerator together for 5 seconds , then within 15 seconds, release accellorator and brake and
press brake and start button. Then press brake and accellerator together for 5 seconds. It says "ready to drive" should be flashing while in diagnostic mode and engine runs continually.
I did not plug in the diagnostic tool, but did everything else. The engine did start when I pressed accellarator and brake together and software rev limiter stopped it just short of 4k. There was no
flashing indication of being in diagnostic mode.
Have you tried this? Do you know what I'm doing wrong? Sincere thanks for anyone that can shed light on this for me. Trans was warmed up when I tried this. I think it's all ok, just wanted to check for correct level.

Sponsored