Newbie Towing Question

[RUSSELL5000]

I took a trip to southeastern Pennsylvania and West Virginia over the past two weekends and week.



I (very foolishly) printed out the driving directions from a mapping software and off we went. In driving from Connellsvilee, PA to Canaan Valley, WV, the route went up a very large hill; this was the section from from Hopwood, PA to Summit, PA on US 40. The average grade is 9%, the maximum grade is 11-1/4%.



The road was being worked on and I was behind a very slow moving truck. I was towing my 30 ft travel traiiler with my 2012 2500 crew cab 4WD. The trailer and load in the truck is right around 85%-90% of what the specifications say the truck can do. I had the exhaust brake and tow/haul buttons on. I pressed the pedal and followed the slow truck ahead of me up this hill; I could only go about 25 mph. I didn't think this was any big deal - the tach showed rpm of around 2000 and we were moving along.



I started watching the temperature gauge and it was moving up. I had never seen that before; the temperature on the EVIC has always been between 201 degrees and 203 degrees, regardless of how I have used the truck. I then started watching the transmission fluid temnperature on the EVIC - it was climbing up as well - the highest I had every seen was about 165 degrees. When we got to the top of this grade, the coolant temperature was at 213 degrees and the transmission fluid temperature was at 210 degrees (according to EVIC). Both temperatures rapidly went down as the road levelled out.



There were quite a few stretches of 9% grades where we were in West Virginia, but we just moved along and I did not observe any changes in the truck at all. When we were running up I-79 on the way home the truck downshifted at one point to climb a big hill on the interstate (tach showed RPM of 2100) and coolant temperature climbed to 208 degrees, but the transmission fluid temperature did not change. This was only for a period of about three minutes and the hill was done.



Questions:



(1) Am I doing something wrong in my driving? It seemed like the truck was having no problems, but the increase in coolant temperatures and transmission fluid temperatures tell me otherwise. I am selecting tow/haul and letting the transmission decide where it should be.



(2) Have I done any harm to the truck? The coolant temperature on the way home was right at 201-203 degrees except on the one big hill on I-79 and transmission fluid temperature were never above 160 degrees.



(3) Is something wrong with my truck?





I'd appreciate insights from anyone.



Observations:



(1) Blindly following a route from a mapping software was about the dumbest thing I have done in a while. There were many alternatives that would have been much easier and much faster. I learned from that experience! I think I will start with the directions in the future and then look at a real map and figure out a good route. I did that on the trip home and it worked a lot better.



(2) If you are RVing and in the northern half of West Virgina, consider the campground at Canaan Valley State Park. Every spot is water/sewer/electric, everything is clean and nice, lots of space between units, the staff were very helpful and service was great, the surroundings are great, and the price is $27 per night.

 

[RustyJC]

According to the EVIC, the engine fan doesn't kick in until 219 degF. I've seen this temperature on some long 6+% grades in 105 degF Texas weather, but as soon as the fan engages, things cool right back down to the normal 201-203 degF coolant temperature. On a long 1st gear pull up the side of a mountain in Arkansas with lots of switchback curves on a summer day towing our 16,000 lb 5th wheel, I've seen transmission temperatures up to 210 degF on the EVIC; normally they'll run in the 160-170 degF range.



Your experience seems to conform to what I've seen.



Rusty

 

[Gonzo 1066]

I would agree, you are seeing normal temps. Engine temps will not be harmful till you are in the 240 range. Trans at 200 is up to operating temps, my new 13 has not shown 200 trans yet, but when I pull a equivilent grade to what you describe I would not be supprised or unhappy.

 

[AH64ID]

Your temps seem normal. Isn't there a way to make the 68RFE lock the torque converter in 2-6 with the ± button? Locking the tq converter will help with trans temps.

As for the engine the 2012s use a 200° thermostat. I haven't been able to find the exact specs on it, but extrapolating data from the Cummins 160°, 180°, and 190° one can deduct the following.

200° ± 3° cracking temp (where 90% of trucks spend 90% of the time)
215°-218° full open
235° max allowed temp.

I have read many posts where the fan kicks on to 100% at 215°, which makes me think that is the temp the thermostat is full open.

 

[jgillott]

Hey Russell5000. You should have stopped in for a cup of coffee on your way by. I'm on top of the mountain near Connellsville.

A better route for you would have been to take toll Rt. 43 south off of 119. It will take you directly to I-68 in Cheat Lake WV bypassing the rt 40 summit. It is a very new road and it may not have been on your software. Next time by this way, that is the road you want.

I've pulled heavy up Rt. 40 many times, usually to drop a boat off in Yough Dam. I doubt that you did any damage under the conditions you described.

 

[RUSSELL5000]

My thanks to all for the insights. Puts my mind at ease. I think this was the first time the truck was really working to get the job done.

I did NOT use the manual shift control - I will look into that idea. I ordered the service manual and have it - but is huge - is that where one finds how the torque converter locks up, etc. ? Apart from this forum, what do you read to understand how the trucks work in more detail? I don't recall such detail from the Owner's Manual.

jgillot - I'll look you up the next time we are down - and I am sure we will be. We stayed at the campground on the river there in Connellsville - nice place. We rode the bicycles on the bike path, kayaked on the Yough, and went down to Ohiopyle for a day of white water rafting. I would like to do some more on the bike on the path - real nice ride. Let me know if you are up in Erie way.

Thanks again.

 

[Hoefler]

The torque convertor will not lock in 1st gear, and 2nd will not lock until road speed is high enough and the torque management tells it to. While towing our 16,000 pound fifthwheel through the Big Horn and the Tetons, I had pegged my transmission gauge in the 08, over 285*, the trans temp light was on, the truck was dinging, all with nowhere to pull over. We were going so slow, the road was very rough from all the construction, I was unable to go any faster than 5-15 mph. I actually stopped and put the truck into 4lo to get the convertor to lock up. When we took off again, the transmission shifted right up to 5th gear and locked up. The transmission temp dropped to normal within 1 1/2 miles and we drove that way for 7 miles. The engine never overheated, the temps were running in the 215* area, the engine fan engaged and stayed on until the transmission temps fell below 200*. All with no ill affects remaining when all done and said.

 

[jgillott]

jgillot - I'll look you up the next time we are down - and I am sure we will be. We stayed at the campground on the river there in Connellsville - nice place. We rode the bicycles on the bike path, kayaked on the Yough, and went down to Ohiopyle for a day of white water rafting. I would like to do some more on the bike on the path - real nice ride. Let me know if you are up in Erie way.

Thanks again.

Absolutely. We head in that direction several times a year. Even if we are just driving by Erie, we always stop in to eat at George's Diner up the road from the Zoo.

 

[JR]

Absolutely. We head in that direction several times a year. Even if we are just driving by Erie, we always stop in to eat at George's Diner up the road from the Zoo.

Don't go too far, you'll end up in the lake :-laf:-laf
We were just in Erie for our annual company picnic at Waldameer.

 

[Bob4x4]

The thermostat will begin to open at 200 degrees f. (93 degrees c),
and will not be fully open until 220 degrees f. (104 degrees c).
If the vehicle has not set a p0217 dtc then a true overheat
condition has not occurred. If a true overheat condition occurs
that sets the p0217 fault code, the mil will illuminate and the
powertrain control module will derate the engine (reduced
torque) to help protect the engine from damage due to high
operating temperatures.

 

[Powder Extreme]

The thermostat will begin to open at 200 degrees f. (93 degrees c),
and will not be fully open until 220 degrees f. (104 degrees c).

Why does the fan come on before the thermostat is fully open? Talking about the new trucks with electronic variable fan control. My fan will usually engage around 208 degrees and be what I assume is fully engaged by the sound around 215 degrees. Hottest I've seen on the motor was 217. Wouldn't it be more efficient, at least fuel wise, to not turn the fan on until the thermostat is fully open and doing the maximum cooling it can before putting additional load on the motor by spinning the fan?

 

[Gonzo 1066]

I assume that the cooling fan may come on early in some hard pull instances to cool the charge air? This is logical to me that there might not be enough air speed going through the intercooler without the engine fan.

 

[AH64ID]

From what I have noticed the fan uses coolant, intake air, a/c status, and possibly ambient air for operation.

If the coolant temp isn't all that elevated but the intake temps are high, above ~130°, the fan will kick on. It doesn't seem to have much effect on the temp of the air in the manifold, but it does lower the intake temp pre-turbo.

 

[Powder Extreme]

That would make sense, to lower the intake air temperature. Didnt think about that.

Mystery solved!