Towing PB engine freakout

[elsinore]

Hi All

I've got a 22' PB lariat Crew cab 6.5 bed with tow package that we have had for a year and 15k miles. Absolutely love the truck.
Zero issues so far and have towed our 25' Winnebago Micro mini a bunch. Probably 4000 towing miles so far. We returned from a 2.5 hour trip today and for the last 40 mins I switched out of tow mode to Eco mode just to see if I could improve mpg as it was mostly downhill/ flat back to the house. The trick worked and I got better tow mileage than I ever have. It also went into electric mode a good amount which has never happened while towing that camper. When we parked the camper back at home I shut off the truck, got out realized I needed to adjust my park job and got back into start the truck up and it had a hideous revving idle with a clunking sound. Shut the truck off immediately and restarted with the same result. The truck also seemed hotter than usual, though the temp gauge did not indicate anything out of the ordinary and there were no engine warnings.

I shut the truck off again and waited about 10 mins, started it up and the rough, revving idle was gone.

Stumped here as the truck is not giving me any indication things are amiss. Anyone have an idea WTF is going on here? Is towing in eco mode a no-no?

Thanks in advance!

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[Old Bear]

I'm making assumptions, but I would say towing in Eco mode is a bad idea. The entire point of Tow/Haul is to optimize the truck for towing. Engine engagement, transmission shift points, fan activation, and I'm sure other things as well are set to handle the extra weight. Switching all that off by going to Eco mode is going to add a lot of stress to a lot of things, even the hi-voltage battery. But as I said, this is me making assumptions!

 

[Porpoise Hork]

It likely went right into high speed idle charging. You likely will need to reset the transmission shift adaptive tables as well. Towing in eco mode will really screw with how the transmission computer will shift. The pressures were way off what it expected them to be for that mode and now it will likely have very odd shifting behaviors in eco, towing and possibly normal as well. Last time I forgot to put it in towing mode when towing it caused some really harsh shifting behavior on the low end that only got resolved by clearing the tables with Forscan and allowing it time to re-learn.

 

[Samson16]

Hi All

I've got a 22' PB lariat Crew cab 6.5 bed with tow package that we have had for a year and 15k miles. Absolutely love the truck.
Zero issues so far and have towed our 25' Winnebago Micro mini a bunch. Probably 4000 towing miles so far. We returned from a 2.5 hour trip today and for the last 40 mins I switched out of tow mode to Eco mode just to see if I could improve mpg as it was mostly downhill/ flat back to the house. The trick worked and I got better tow mileage than I ever have. It also went into electric mode a good amount which has never happened while towing that camper. When we parked the camper back at home I shut off the truck, got out realized I needed to adjust my park job and got back into start the truck up and it had a hideous revving idle with a clunking sound. Shut the truck off immediately and restarted with the same result. The truck also seemed hotter than usual, though the temp gauge did not indicate anything out of the ordinary and there were no engine warnings.

I shut the truck off again and waited about 10 mins, started it up and the rough, revving idle was gone.

Stumped here as the truck is not giving me any indication things are amiss. Anyone have an idea WTF is going on here? Is towing in eco mode a no-no?

Thanks in advance!

I’m thinking heat soak management confusion after turning the engine off following low rpm loading

 

[dogboye]

Note to self: never, ever, tow in Eco mode!

 

[RickBullotta]

Hi All

I've got a 22' PB lariat Crew cab 6.5 bed with tow package that we have had for a year and 15k miles. Absolutely love the truck.
Zero issues so far and have towed our 25' Winnebago Micro mini a bunch. Probably 4000 towing miles so far. We returned from a 2.5 hour trip today and for the last 40 mins I switched out of tow mode to Eco mode just to see if I could improve mpg as it was mostly downhill/ flat back to the house. The trick worked and I got better tow mileage than I ever have. It also went into electric mode a good amount which has never happened while towing that camper. When we parked the camper back at home I shut off the truck, got out realized I needed to adjust my park job and got back into start the truck up and it had a hideous revving idle with a clunking sound. Shut the truck off immediately and restarted with the same result. The truck also seemed hotter than usual, though the temp gauge did not indicate anything out of the ordinary and there were no engine warnings.

I shut the truck off again and waited about 10 mins, started it up and the rough, revving idle was gone.

Stumped here as the truck is not giving me any indication things are amiss. Anyone have an idea WTF is going on here? Is towing in eco mode a no-no?

Thanks in advance!

Yikes. I wonder if you damaged the electric drive system (tow/haul locks out electric only drive mode). I stick to tow/haul mode with my 5000 lb travel trailer just to be safe.

 

[Atlee]

It likely went right into high speed idle charging. You likely will need to reset the transmission shift adaptive tables as well. Towing in eco mode will really screw with how the transmission computer will shift. The pressures were way off what it expected them to be for that mode and now it will likely have very odd shifting behaviors in eco, towing and possibly normal as well. Last time I forgot to put it in towing mode when towing it caused some really harsh shifting behavior on the low end that only got resolved by clearing the tables with Forscan and allowing it time to re-learn.

After reading your's and Old Bear's posts, I will make sure I only tow in Tow/Haul mode in the future. While I've never towed in Eco mode, I have done extended runs in Normal mode. I've yet to have any negative reactions, out of an abundance of future caution, I'll stay in Tow/Haul.

 

[Tosh]

I've used Normal mode when towing a 2.5 ton RV around town, max speed 40 mph. Haven't experienced any problems with it.

 

[Hullguy]

I’ve towed thousands of miles in Eco Mode with no issues. Also Normal Mode.

 

[DcnPat]

I've got to believe if towing in eco mode would damage anything there would be a noticeable warning in the manual and one that appeared in the truck when you selected eco mode with anything connected to the trailer electrical connection.

 

[JIMFOUNTAIN]

I’m thinking heat soak management confusion after turning the engine off following low rpm loading

It seems to come back to this as a likely cause.

 

[amschind]

Do you have your transmission temperature displayed on your cluster? If so, what was it before and after shutdown/startup?

 

[MattM]

Just towed a Lance 2375 about 6500 miles using Normal Mode with no problems. Surprised to hear using Eco would cause problems beyond a possible loss of performance.

 

[Snakebitten]

These "modes" are almost nothing more than different 10r80 shift strategies. (along with throttle tip-in mapping)
Ford then gives the shift strategy names/labels to identify the shift strategy with a description that we can associate the strategy with.

Tow Haul describes a shift strategy that a 10r80-transmission engineer would determine is appropriate for the 10r80 under additional load/burden beyond the truck itself.

I always imagine the truck having a manual transmission, and when would I choose to shift under the current circumstances?

Eco mode would rarely represent my personal shift points. Certainly not under towing burden. It's like riding a 10 speed bicycle and intentionally getting to thigh-burn ratios as soon as possible. In my opinion it stresses everything in the drivetrain unless you accelerate at a very conservative rate.

 

[stonefly]

I use TOW/HAUL when I'm in a lot of hills although I've used NORMAL for bulk of towing, even on hills. When in NORMAL, I use the cruise control to limit downhill speed in EV periods, with ICE turning on as needed to maintain selected speed.
I like using 4A, NORMAL mode. I found a passage in the owner's guide that indicates you should not use 4-wheel drive on roads continuously, so I'm reconsidering 4A next time I tow. I can feel a significant difference in tactile feedback in 4A v. 2H.

In one of the towing threads it was stated that TOW/HAUL reduces coolant temps; I tested that out a bit (normal v. T/H, no trailer, 50 MPH) on a 2-mile 6-8% grade. T/H got hotter by 10-15 degrees F and took longer to cool back to baseline of 185 degrees F. Sample size 2 runs per mode.
Now that I have OBDLink PID monitoring, I'll be collecting more data that I may be able to use to understand what seems to influence coolant and tranny temps.

I figure if there were a real problem with towing in NORMAL, Ford would've restricted me to T/H.

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