Towing and Empty Temps

[ctechbob]

Here's some data I grabbed the other day. Not a particularly hot day or hard tow, and I'll try and get some more as we get into hotter temps down here. Just showing that towing big heavy things really doesn't have as much effect on the transmission temps as you would thing with this truck.

I had to take the camper up to the shop for some warranty repair the other day, and since I didn't need my 'navigation' phone for, well, navigating, I decided to reinstall Torque Pro and do some temperature logging. This is pulling our 26DJSE that clocks in at about 5800# and is a full 8' wide trailer. No highway running on this route this time, just 45-55mph state roads.

I should have spent some more time with the setup, I meant to grab speed but missed getting the PID in the capture. I'm capturing at twice a second.

In all, I captured:

Coolant Temp
Transmission Temp
Intake Air Temp
Outside Temp
RPM
Boost/Vaccum
Timing Adv/Retard

First the Towing plot. Starting from a stone-cold (78ish ambient) truck. The three humps where the trans temp climbs up to 210 or thereabouts is where I was crawling through traffic, climbing hills don't really have any effect on the temp, but then again I'm not climbing mountains, just rolling hills. Keeping in mind that this trans is cooled by a liquid/liquid heat exchanger that appears to do a pretty good job of keeping temps right where they want them. As soon as you get out of traffic and the coolant in the radiator drops, the trans drops back down to 200.

Now for the Empty Log after dropping the trailer off.

You can see where there is some intake heat soak as I left the RV dealer with elevated intake temps. The second bump in intake temps was me sitting in the drive-through at Chick-fil-a and the 3rd is sitting at the gas station, engine off (Lower overall temp).

As for the transmission temps, they are lower for sure, but I was also not in as much traffic, so the coolant in the radiator should have been slightly lower.

Sponsored

 

[Racket]

I'm impressed the trans temp stayed as low as it did in both scenarios.

Is everything stock? Any add ons or tune?

 

[Jason B]

Good data. But engine coolant shouldn't change much as it is thermostatically controlled. Plus the radiator fan is controlled by ECM too. You would probably see a steady temp around 200, whether the outside temp is 90 or 9.

And with all the complaints about 'a poorly designed transmission', trans temp looks good even when towing.

 

[Grumpaw]

Just finished a run towing our 7000 lb Jayco from Va to Delaware coast, around 285 miles. Via I-81, I-66 and around Wash DC. Ran 60-65 on the interstates and crawled around I-495 around DC.
Air temps were 65 to 82 at the end.
Via my Scan Gauge 3 coolant temps ran from 198 to 205 while in stop and go traffic.
Trans temps got to 211 at several points in traffic crawling around I-495 but both dropped to 200-205 once we got thru the mess. Pretty much stayed at 200-205 when traffic flowing at 60-65.

 

[ctechbob]

Good data. But engine coolant shouldn't change much as it is thermostatically controlled. Plus the radiator fan is controlled by ECM too. You would probably see a steady temp around 200, whether the outside temp is 90 or 9.

And with all the complaints about 'a poorly designed transmission', trans temp looks good even when towing.

Correct on the engine and fan. Mainly what we're seeing in this data is:

1. Ford is making sure that the trans runs in a very narrow range of temps, between 190-220 from the looks of it.
2. The radiator has enough cooling capacity to deal with both the engine and trans heat that it is needing to shed.

What I don't have is fan speed data. I don't think that is going to be in generic OBD2, but I might pull out my ForScan stuff and do some more with it this summer if I have time. I'd love to see the fan PWM signal in regards to heavy loads and outside temp.

I was really hoping for a hotter day to do this on, but temps here in GA have been crazy cool for this time of year.

 

[Big Blue]

What I don't have is fan speed data. I don't think that is going to be in generic OBD2, but I might pull out my ForScan stuff and do some more with it this summer if I have time. I'd love to see the fan PWM signal in regards to heavy loads and outside temp.

Not sure how much fan data you are going to find, as our fan is driven by the engine through a clutch arrangement. So I don't think there is any speed feedback.

 

[ctechbob]

Not sure how much fan data you are going to find, as our fan is driven by the engine through a clutch arrangement. So I don't think there is any speed feedback.

Might be surprised. I know Dodge has feedback in their engine-driven fan controller.

I'd almost be willing to bet that Ford works similarly to the Cummins in this vid.

--Edit-- Just went and looked, ours is a 5 wire setup as well, so it is probably PWM with feedback.

 

[ctechbob]

I'm impressed the trans temp stayed as low as it did in both scenarios.

Is everything stock? Any add ons or tune?

Sorry, forgot to answer this one.

Completely stock drivetrain. No add-ons, although I am doing the PPE pan this weekend, pretty much the only reason is for the drain plug. I do regular D&F's of the fluid and having a drain plug will be a big win. I'm doing the shallow pan as opposed to the regular. I don't think there's anything to gain, for me, with the deep pan.

 

[Jason B]

Correct on the engine and fan. Mainly what we're seeing in this data is:

1. Ford is making sure that the trans runs in a very narrow range of temps, between 190-220 from the looks of it.
2. The radiator has enough cooling capacity to deal with both the engine and trans heat that it is needing to shed.

What I don't have is fan speed data. I don't think that is going to be in generic OBD2, but I might pull out my ForScan stuff and do some more with it this summer if I have time. I'd love to see the fan PWM signal in regards to heavy loads and outside temp.

I was really hoping for a hotter day to do this on, but temps here in GA have been crazy cool for this time of year.

I haven't looked, but I believe that there is no active cooling/heating loop from our trans to the radiator. We have a heat exchanger to keep temps steady, but no coolant loop.

I'm interested in fan control, as I assumed it was just ON-OFF using both temperature and ECU controlled viscous clutch.

 

[ctechbob]

I haven't looked, but I believe that there is no active cooling/heating loop from our trans to the radiator. We have a heat exchanger to keep temps steady, but no coolant loop.

I'm interested in fan control, as I assumed it was just ON-OFF using both temperature and ECU controlled viscous clutch.

Not sure I follow you there. The heat exchanger they use on our trans is both a warmer and a cooler. The coolant flows through it and is controlled by a valve. When cold, the coolant is used to heat the trans fluid, and once up to temp it is used to regulate the temp. If the trans fluid is hot, it sheds that extra heat into the main raidator via the coolant.

As for the fan, I'm just assuming it works the same/similar to that Dodge video. It may well be off/on, but with 5 wires, it is most likely PWM, since off/on would cost more fuel.

Nothing is simple anymore.

 

[RangerBill]

The PCM monitors the fan speed and controls it. If I remember correctly, you can view it with Forscan.

 

[yamahaSHO]

I'd be curious to see the same tests done at high altitude (6k +).

 

[Grumpaw]

I'd be curious to see the same tests done at high altitude (6k +).

A lot of the data will be dependant on outside ambient temperature, load, speed, tranny gear....
We towed our rig on I-40 west out of NC into Tenn....lots of grades, slow-downs, ect running from 40-65mph. It was in April with air temps of 50-60, and veh fluid temps never got over 200-205. Also, when I tow, it's in tow mode (always) and in 8th gear, and 7th gear in mountain and hilly terrain. Temps on our currant trip were higher, but ambient temps were up to 81 degrees with lots of slow downs due to heavy traffic.
I am impressed with the cooling of the Rangers fluid temps while hauling my heavy trailer....much better than many other rigs/motorhomes we have had in the past. As a loooong time rv'er, my first worry when towing is the fluid temps as when they get "high" it's time to worry.
After almost 2 years with the Ranger, I don't worry at all.

 

[yamahaSHO]

A lot of the data will be dependant on outside ambient temperature, load, speed, tranny gear....
We towed our rig on I-40 west out of NC into Tenn....lots of grades, slow-downs, ect running from 40-65mph. It was in April with air temps of 50-60, and veh fluid temps never got over 200-205. Also, when I tow, it's in tow mode (always) and in 8th gear, and 7th gear in mountain and hilly terrain. Temps on our currant trip were higher, but ambient temps were up to 81 degrees with lots of slow downs due to heavy traffic.
I am impressed with the cooling of the Rangers fluid temps while hauling my heavy trailer....much better than many other rigs/motorhomes we have had in the past. As a loooong time rv'er, my first worry when towing is the fluid temps as when they get "high" it's time to worry.
After almost 2 years with the Ranger, I don't worry at all.

Lack of air is lack of cooling via air. Take all those grades and remove 30% of that air and that is the data I am curious about.

 

[ctechbob]

Lack of air is lack of cooling via air. Take all those grades and remove 30% of that air and that is the data I am curious about.

Would be nice to see. I'm not going out west anytime in the next several years though .

I know TFL managed to overheat their Powerboost 3.5, so I would imagine you'd start seeing elevated temps in a Ranger as well. Especially if you didn't take into account their 10% for every 1000 feet or whatever it is.

Sponsored