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Towing Review//Engine Heat

24K views 91 replies 35 participants last post by  Scott Weldy 
#1 ·
Thank you to so many who have written terrific reviews. Some of you are household names over the past few months. This is my first as I did not have much to add until now. The SFU is now about 2 1/2 weeks old and every bit the vehicle I expected. Even superlatives don't do it justice. However, during our first tow, we noticed the same issue reported by our brethren in Oz, with respect to engine temperatures on grade. I know there's another thread but I thought I'd post here as it's in the states and would welcome comments and advice. Here's some early data.

I have the Limited 4x4, ORA II, Adv Tech, etc... Everything possible for towing.

We live in San Diego with moderate temps year around as everyone knows. Drove 90 miles to the RV dealer yesterday to pick up our new 28 foot travel trailer with a dry weight of 6100. Equal-i-zer hitch. Tekonsha P2 controller. Route back was via a couple of SoCal freeways, with several short and moderate grades. Nothing challenging. Chose to baby it at 50 mph for the most part. Dropped to 40 in some light traffic. Never over 55. Handled very well. My old setups were 4x4 Suburbans with large V8s and a 5500 lb dry trailer. The handling on the flats yesterday was excellent. Didn't feel like there was any extra effort. Maintained RPMs at 1500 in Eco. Transmission temp at 190 give or take and oil temp at 210 give or take. OAT at 70.

Things changed on the grades. These were nothing like the grades we expect to challenge later with the trailer: Sierra, Rockies, etc... Just modest uphills for a few miles.

The temp gauge almost immediately registered increases. If the hash marks on the main gauge are divided in eighths, baseline was at the 3 and it quickly jumped to the five mark. Oil/transmission temps rose quickly to 230/197. I exited Eco and downshifted to 5th and 4th, trying to find a match. The transmission responded and I felt the expected surge. 5th jumped to 2600 RPM and 4th to 3500.

A later grade saw the oil temp rise to 246 and I dropped speed to below 50. Gauge close to redline.

I towed it about 20 miles today and experienced the same response.

It never hit redline on temp but I don't know what that actually means. I don't have a fraction of the mechanical know how of many on this forum. Just a love for the great outdoors and all of the versatility the Diesel JGC offers. Am hoping there's some reasonable answer so I don't have to be anxious about it performing to its specs. I assume engine heat should not be a problem for regular grades in the U.S. in moderate climate conditions so long as the trailer is under 7200 lbs and properly equipped. Any advice would be appreciated. Thank you.
 
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#2 ·
Interesting. Although I was not towing, I experienced a similar heating issue tonight trying to make it up my private road. I have 990 miles on the Jeep. Going up a snow/slush covered grade in snow mode the traction control brought the Jeep to a dead stop (I haven't swapped the factory Michelin Latitudes for snow tires yet). I backed down the hill, put it in low range, and powered my way up the hill. I was surprised at how quickly the engine oil temp climbed from 200 to 225 along with the coolant temp climbing along with it. The transmission oil temp never climbed above 197. The OAT was 30 F.

I wonder if spooling the turbo for any length of time sends the temps skyrocketing. Like you, I intend to tow a travel trailer, but now I'm a little concerned after seeing how quickly the temps shot up just climbing up my driveway.
 
#3 ·
There is another thread that was started on high temps while towing. I am very concerned about this. I plan to buy a 1500 ram with the same motor. Like I said in the other thread the duramax had this issue in 05' and ended up buying back a lot of trucks. I would keep a log of this and I know guys were providing video proof.
 
#4 ·
I am interested in hearing what Chrysler has to say. I know from my Super Duty that my oil temps and trans temps never approached much over 190F.
However that was an older 7.3 turbo diesel.
My 335 BMW twin turbo runs 245F as the regular oil temp. Is it possible that this VM diesel runs hotter like this?
I know the transmission temp is designed for 176F and there is a heater in the Ram and I think also our Jeep.
You know that they had to test these in hot conditions so they had to see temps like this.

Boy sure hope that what you guys are seeing is considered normal because none of these cases are pushing anything very hard.
 
#5 ·
Yes, spooling up the turbo will cause the coolant and oil temps to rise. I used to own a RAM 3500 Cummins. The primary concern when towing with a turbo diesel is the EGT (exhaust gas temp). When you start running much over 1300*, you risk melting pistons. Long grades while pulling a load requires much more effort from the engine. This requires more fuel which produces more boost and increases the EGT. The increased cylinder temp causes the increased oil and coolant temps you are seeing. The easiest way to control EGT is to control the load on the engine by locking out the higher gears when towing a grade.

Wonder what the EGT is when you are experiencing the high temps? May need to install a pyrometer to make sure you are not getting into the danger range for temps.
 
#6 · (Edited)
Wonder what the EGT is when you are experiencing the high temps? May need to install a pyrometer to make sure you are not getting into the danger range for temps.
That is a spot on description of EGT cause and effect. Lugging a diesel creates high EGT even when loads aren't maxed out. Keeping RPMs up in the 2200+ range helps under heavy tow conditions. Also more water is circulated.

The GC CRD has an EGT sensor built in and its reading is visible via ODBII using the Torque App on an Android device with an ELM327 Bluetooth adapter plugged in the diagnostic port. I have no idea if its pre or post turbo but it changes rapidly. I have seen 1200 F at wide open throttle and 8th gear at 70 mph on flat ground runs 650 to 720 F. During DPF Regen the Cat Temp (also visible) and EGT went to 1200 F for several minutes.

Anyone towing should invest in a Torque App setup. I have $30 total invested.
 
#7 ·
A couple things that might be of interest.

On the trucks the gauges are dummies and their readout is dithered by the computer so as not to alarm customers. An example would be they show a higher than actual oil pressure at idle. This has been the case since the 3G trucks came out in 03 and applies to all the gauges. Whether our Jeeps have this going on as their brothers over at Ram do I don't know but if forced to put a shiny new penny on the line I would bet they do.

As to oil temp I can make some generalizations. The engine can withstand much higher temps than the oil can. The oil itself can see up to 600° at the top ring in a diesel engine but this exposure is too transitory to break down the oil and that is where you run into trouble. When the oil breaks down it loses its ability to provide the protective film that is preventing whatever parts are being lubricated from becoming biblically acquainted. This is what we care about, preventing this break down in the oils ability to lubricate.

Exact numbers cannot be given because they're effected by viscosity, contaminates suspended in the oil, desired oil service life, and many other factors. As a general rule of thumb 230ish for conventional oil and 270ish for synthetic oils are around the max sustained you typically see recommended.

To go back to the beginning I would be watching that temp closely and paying attention to its behavior. I would be under the expectation that it is not telling me the real temp but rather what Uncle Jeep wants to tell me. I would be watching to see if it climbs to a peak and camps at the same spot on steep but varying grades. I would watch for it to cool down at the same rate it warmed up after I reached the crest of the hill. Both combined are giveaways that your numbers are dithered. From there you have to decide what it means. We know that these vehicles have had extensive hot weather testing unloaded, loaded, and towing. We have to figure that Jeep does not want to provide a whole lot of new engines and other expensive parts to customers that were towing within the lines. The implication to me would be that it can (probably) safely tow up to its rating in all but extreme conditions based on that alone. I also would note that while several have sited high temps shown I haven't seen anyone say they actually had the vehicle overheat. A big difference between this vehicle and the Chev trucks mentioned previously.

I hope I didn't raise more questions just trying to keep it objective.
 
#8 ·
To go back to the beginning I would be watching that temp closely and paying attention to its behavior. I would be under the expectation that it is not telling me the real temp but rather what Uncle Jeep wants to tell me. I would be watching to see if it climbs to a peak and camps at the same spot on steep but varying grades. I would watch for it to cool down at the same rate it warmed up after I reached the crest of the hill. Both combined are giveaways that your numbers are dithered. From there you have to decide what it means.
That's interesting. The gauges showed dramatic increases and decreases rapidly, when climbing and after cresting. Pretty much the same rate. As I mentioned in my original post, I do not have the mechanical savvy to interpret all this in a way that will relieve anxiety. So far, it seems I either have to trust Jeep (which I'm willing to do to a point) and the engineers/specs, or I'll need guidance on how to resolve the situation relatively simply. Appreciation to those with expertise chiming in.
 
#9 ·
No they may not have overheated yet but so far we have been shown relatively light loads and really low oat. I am hoping this is not an issue for these vehicles, I have my heart set on a ram eco. But we can't assume that there may not be a problem. Even if the gauge was 5% off it is still close to the 225*f mark that I wouldn't want to go over.
We need to hear from more people hauling 6500lbs on a 95* day.
 
#10 ·
We need to hear from more people hauling 6500lbs on a 95* day.
tall order, diesels have been on the market for 1 month and north America is heading into the winter season.

why don't you guys organize yourselves and test under some controlled conditions. Same incline, same road, speed and load, several cars, same environmental factors. Throw in for shit and giggles a v6 and a v8 and watch their temperature gauges. Ideally you'd monitor and log the data via OBD-2.

I agree that the gauges are not the best indicators, the temp gauge is for relative readouts at best. But the sensors, with numerical values, those will generally be accurate. Some are tied to pollution control equipment and risking the wrath of EPA is not worth for any manufacturer.

I don't know about your engine but I know a bit about turbos. On my Subaru, the turbo is cooled and lubricated from the general engine cooling and lubrication circuitry. Over the years, Subaru changed the location of the feeder and return lines for some of the models specifically for those reasons. It makes a difference where these lines are connected as it determines the temperatures of the fluids reaching those parts, as it also matters where in the system the sensor is. I will not get into the Subaru details, lets just say that mid way thru 2008 there was a production halt due to failing turbos and pieces sucked into the engines. And that is how Subaru moved to a mandatory 3800 mile oil change interval for all turbo vehicles along with some re-engineered parts.

I hope Jeep sorts it out for you guys.
I now wonder how the diesel truck will fare in off-road, as that work regimen would also overheat the drivetrain
 
#11 ·
Some fair points made and I think it's interesting to note that the Gents down under are reporting the same temps in much hotter ambient temps. This is not possible unless the cooling system is designed to run at that temp under load and the system is holding the temp there or this is simply the temp Jeep design and engineering have decided the gauge will tell us.


Either way the real proof will be in the pudding.
 
#13 ·
Hey Brad, thx for the pm.. I'll forward your post to one of the good ppl upstairs bc I'm curious abt this one myself. I've seen similar things in various different semis when climbing steep grades, but it's usually from hauling loads well over the allowed gross. So it's expected. But considering you're well under, it seems a bit strange.

But I don't wanna start shooting in the dark to give you an answer when I can just ask someone. So I'll let you know when I hear something back. But in the meantime, I'd go get an oil change and inform your dealer abt this potential issue.
 
#24 ·
Thanks, Chevy. Just back from a few days up in the mountains without the trailer (the JGC is perfect for the newly-retired). Will haul the trailer over to the beach at Camp Pendleton tomorrow for a week. (Sorry to others in the US suffering from miserable weather. It's going to be below freezing here, which is unusual but not in the same universe as many are suffering now.) No grade so won't be able to test its response again until January. Would still appreciate feedback from experts at Chrysler/Jeep or elsewhere as to whether the observed data is reasonable or not. And, if not, what the corporate solution is. I'll follow other advice in this thread and make sure not to tow in eco, downshift within reason, change the oil soon, etc... But, I look forward to more information and a long term solution. Don't believe I should have to shell out for additional equipment when I'm within the advertised specs.
 
#16 ·
First thing I'd do towing that weight is Keep Eco Mode OFF.
It probably won't make much difference in economy on the highway.
It will stay in gears longer from stand still.
My guess is, it might be in the manual.
I doubt it would solve your heating issue, but it's pretty standard to shut stuff like that off when towing that kind of weight.
 
#17 ·
I sure would like to know what the nominal temperatures are for oil-transmission-coolant. From reading on other forums where turbo engines are used the trend seems to be moving up in temps. Designed temp for the transmission is 176 and in the Ram and I think too the Jeep there is a heater to keep it that warm or warmer.
Oil temps since it is using synthetic oil seems to be running 240-245F which according to other forums helps reduce emissions. Not sure what the coolant temp is designed to be but if the rad cap is say 28-30 psi higher temps would not cause an issue either.

I am hoping and that is the key word hoping that this is what Jeep had in mind. Newer technology-reducing emissions-higher temps...
 
#22 ·
There are multiple seller of ELM327. I just used the one that is on Ebay and has good seller feedback. If you are using BT it is about 11-14 bucks
If you use wifi it is about 22-27 bucks. I have bought 3 ELM327's for wifi for my use and friends.
Just make sure you get BT if you are using android and wifi for iphone/ipad. Not torque app for iphone using wifi by the way unless they just changed something.
Hope this helps.
Also get the latest software version which I think is 1.5 but check..
 
#26 ·
I'm waiting on Jeep to let me know if this is a problem or normal operating conditions.

Many of us in the BMW camp freaked out at seeing 260F oil temps and coolant temps when the 335 twin turbo came out. Typical operating temp is 245F for the oil same for the coolant. This was 2007.

All about emissions. Hotter they run the better it controls the emissions output according to BMW>

Since the diesel is supposed to have the HD cooling temps running high should not be an issue but I for one would be really concerned seeing anything running close to the red on cooling.

My SuperDuty with flash program never reached 210F on trans temp or oil towing a large sailboat which was maybe 5000 pounds during the summer Florida heat. Hardly knew it was there.

Come on Jeep give us the scoop on these temps, normal, not normal or what!!!!
 
#27 ·
These temps are nothing to worry about.
If the temps are actually too high (either being turbine inlet temps, coolant temps, engine oil temps) the engine is going to automatically derate itself for protection. You can foot to the floor with a max trailer all day long and the engine will just chug along.

No trans oil heater on the WK, only DS.
 
#28 ·
A brief recap of my first towing experience with my CRD:

- towed a 25' Airstream from Las Vegas to Pasadena and back.
--GAWR Front Actual 3140 lb
--GAWR Rear Actual 3700 lb
--Trailer 6600 lb
--Combined trailer/vehicle 13440 lb
--Average OAT 60 F
--Propride 3 Hitch and Direclink brake controller

- EVIC fuel milage averaged 19.5 mpg to Pasadena and 18.4 on return trip
- Engine performance
--EVIC oil temp climbed to 257 on long uphill pulls
--Coolant temp climbed to on notch below red area on gauge
--Slowing from 55 to 50 mph stabilized engine temps
--Temps quickly recovered on level or downhill grades
--Engine torque and power were not an issue
- Transmission performance
--EVIC transmission temp climbed to 203 once, but mostly stayed at 195
--Gear shifts were smooth and appropriate for the load (ECO mode OFF)

- The CRD now has 4300 miles on it. The EVIC oil life indicator is at 49%
and the DEF is a little under half a tank remaining.
 
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#29 ·
Thanks, Talltale. This is very helpful. Sounds like we're pulling similar weights and you challenged some higher grades than I have to this point (I think the Cajon Pass is around 4000 ft.). We plan to travel into the Sierra this summer and Rockies next fall. Would you have any trepidation, given your experience? I hope others post their results as most of North America moves into the travel season this spring. Would also still like to hear from Chrysler that these spikes are nothing to be concerned about and that we can safely endure those temps for extended periods.
 
#32 ·
I like to keep my engine oil temp in the range of 210 to 250 F. I'm under the impression for most modern oils thermal breakdown starts at around 275 F. I'll be the first to admit I'm no oil expert. I also would like to hear more from Chrysler on this topic.
 
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#33 ·
I did quite a lot of searching without hitting pay dirt on our specific oil. I did find several similar synthetics that were being tested at 150C for 100 hours by the manufacturer without significant breakdown. There is quite a large body of evidence indicating that the upper 200s is safely within the limits of modern synthetics. Not just anecdotal but also coming from reps from the oil companies. I notice for instance on Mobil's site there is a section where you can ask questions. A person asked if he was in trouble with his oil temps on his race car which were seeing 240C at the turbo outlet. The engineer that responded said that was not surprising and that Mobile 1 could hold up to intermittent temps in that range but that oxidation would occur and the oil should be changed every race. There are many such examples for those that want to search.

The intermittent part is something else to think about because it is actually a defined place. I've included a link to a youtube video that will likely bore a lot of people discussing some things about oils and temperatures. Its a rep talking but there is some good information. AMSOIL Normal and Intermittant Oil Operating Temperatures - YouTube

For my part I'm not worrying about the temps reported until someone gives me good cause to be. Everything I know or can find says that the oil temps reported could be higher and I'd still be fine. I can also click search page after search page and not find any of our friends down under that hit an actual high oil temp fault/alarm and they've had this engine operating in high ambient temps for a while now. Since I'll be towing come spring I will soon be a data point myself I suppose.
 
#37 · (Edited)
Now if you look at my signature you will see that I am biased towards Amsoil, buuuut I can certainly attest to the performance of their oils. Two independent companies took my UOA on a race bike that had 1000 race miles on the oil. That is 1000 miles at an average of 10,000 rpm and coolant temps >220*f. They confirmed that I could run that oil longer if I wanted to.
FWIW, you do not have to pay the dealer fee to buy Amsoil. Anyone can. It does offer some discounts though. So if you are doing 2 oil changes a year the savings more than cover the fee.
The intermittent part is something else to think about because it is actually a defined place. I've included a link to a youtube video that will likely bore a lot of people discussing some things about oils and temperatures. Its a rep talking but there is some good information. AMSOIL Normal and Intermittant Oil Operating Temperatures - YouTube
Nice find, Crabman! I knew there was nothing to be concerned about until well over 300*f but couldn't remember how high.
I'm under the impression for most modern oils thermal breakdown starts at around 275 F.
Nope ;) fast forward to the 4:09 mark in Crabby's video.
FWIW there are thousands and thousands of Harleys running stop and go traffic in summer heat at 260-270 oil temps without any adverse effects on the oil. I have seen mine there many times.
Yessir! I got caught in weekend traffic at Niagara Falls and had 277* oil for probably 30+ minutes on my R1200 (air cooled boxer). No warning lights. I sent the oil in for a analysis at 5000 miles and was told it could go longer.
 
#34 ·
My twin turbo 335 BMW is designed to run 245F and I have seen 270F. It will go into limp mode when over 275F. Mandatory to run approved synthetic oil but what we have spec'ed is much better meaning lower ash and good HTHS numbers which is how I think they get away with 10K oil changes.
I can see this engine 3.0 VM, running hot all the time as that reduces emissions, hot meaning well over 210F which in the old days was bad news. Also our transmission had a heater in it to keep the temp at 174F or higher.
I too am waiting to hear from Chrysler but they seem silent on this topic so far. My guess is that we are all fine running these temps. My experience with diesels is the hotter they run the better they run...
 
#36 · (Edited)
BradSD, some good info from the previous posters. Let me add some of my Ram 2500 towing pearls to your information.

1. Please be careful towing with your rig, because even though "1500" trucks and crossover vehicles are touting high tow rates, and RV dealers will let you leave with anything which will move the trailer, you can find yourself in a bad situation real fast towing with a smaller vehicle. I'm not doubting your towing ability, nor driving/towing skills. I'm only saying what I've seen happen in real life while towing on the road. IN the blink of an eye, you can find the the "tail wagging the dog", from say, a crosswind, or an aggressive driver causing you troubles.

2. With regards to engine temps, and such....When approaching a grade, I would select the lowest gear which doesn't approach the redline, as this will allow the whole machine to operate in less of a "%load", or what amounts to lugging the engine. You'd think the engine tranny would automatically take care of this, however, remember CAFE and you'll understand. I've watched my EGTs (exhaust gas temps) climb on my Ram towing our 5er, and just gearing down 1 or 2 gears allows me to maintain speed while maintaining much lower EGTs. You'll quickly get used to how your GC feels when it's starting to lug. Just read the terrain ahead, and even on a mild grade just downshift 1 or 2 gears and let everything "relax a bit". Then, if you are still feeling increasing throttle input, maybe gear down one more. The GC shouldn't let you downshift into an over-revving situation.

I do not know this to be a fact with our CRDs, but I would bet the engine would "defuel" before you will melt anything EGT related. Said another way, I don't think the 3.0 is gonna grenade, as I think it has safety factors and protective logic built into the tune.

3. Also, selecting a lower gear on grades helps protect the transmission, again by giving the transmission some mechanical advantage.

IF you are moving slowly at a campsite, or having to slowly climb a moderate to severe grade, select low range, if you have that option. That will really alleviate heat build up from a slipping torque converter. (Many a 2500 has boiled it's tranny fluid pulling up some tall grades, in high range, leading to parking areas at our motorcycle races.)

4. As fun2drive suggested, check into the Amsoil engine oil offering. If you pay a small yearly fee, you can get the oil for 8.50 a qt.

5. The oil life monitor will take into account your driving habits and you can expect a shorter oil duty cycle if you tow much. If you prefer to stick to your own oil change schedule, that's ok by me as well.

Just wanted to throw in a tow pic of picking up our 5er a few months ago.!

 
#38 ·
This whole discussion rings of a conversation I had with the makers of the motorcycles I ride. They added a system voltage monitor to the instrument cluster, and people were freaking out about how the V dropped at idle. "Too much information at the customers hands is NOT always a good thing".

Basically...if the light doesn't come on...don't worry about it.

Sure, we're seeing higher temps than we're used to. But speaking from personal experience...I'm "used to" seeing the temps that my '72 Satellite will run, or my 220k mile '01 Cummins will run. New engines, and new fluids, have much higher tolerances and specs than the older ones. And don't forget this engine requires a SPECIFIC oil - probably...for a reason.

Yes, EGT is the concern for a diesel when towing. I have boost and EGT gauges in my Cummins (it's a stick so no use for trans temp). It's a six speed. When towing (I work for an RV dealer so it happens a lot) I will downshift from 6 to 5 for even the slightest grade. Not only does it keep me from losing MPH, but it knocks a few hundred degrees off my EGTs. In automatic-speak....take it out of Eco, or put it in Sport. More RPM will equal more airflow through the engine, more coolant flow through the engine, more oil flow through the engine...and lower EGT's. Sure, lower RPM means better MPG...but for a couple bucks in fuel, I'd rather take better care of my engine internals. And to clarify a statement made earlier in the thread - more fuel flow equals LOWER EGT's. Fuel is a "coolant", if you will, and engines run hot when they run lean. In racing-speak - "lean is mean"...but you can melt important things like valves or pistons if you're too lean and too hot. Goose it and throw some more fuel at it, and it'll cool it off a bit.

Remember - our VM Motori's are high tech. Cooling oil jets spray the underside of the pistons. The rods are cracked-iron design with angled cap seams for clearance, because they're so beefy and wouldn't fit with a standard 90 degree seam. The mains aren't individual, but girdled...and they're still four-bolt design. The oil sump pickup tube is the same size as a Duramax tube. This is a pretty serious motor.

If it were me towing with one (I have the Cummins, so that gets my "drag something heavy" work), I'd slap it in S mode and go. If the warning light doesn't come on...don't sweat it. And, follow your "severe duty" oil change schedule.

And any time you work it hard...MAKE SURE YOU IDLE IT FOR 90 SECONDS BEFORE TURNING IT OFF. That circulates cooling oil and coolant through the turbocharger, and keeps it from "coking" into dry carbon and ruining your turbo.
 
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#40 · (Edited)
Yes, EGT is the concern for a diesel when towing. I have boost and EGT gauges in my Cummins (it's a stick so no use for trans temp). It's a six speed. When towing (I work for an RV dealer so it happens a lot) I will downshift from 6 to 5 for even the slightest grade. Not only does it keep me from losing MPH, but it knocks a few hundred degrees off my EGTs. In automatic-speak....take it out of Eco, or put it in Sport. More RPM will equal more airflow through the engine, more coolant flow through the engine, more oil flow through the engine...and lower EGT's. Sure, lower RPM means better MPG...but for a couple bucks in fuel, I'd rather take better care of my engine internals. And to clarify a statement made earlier in the thread - more fuel flow equals LOWER EGT's. Fuel is a "coolant", if you will, and engines run hot when they run lean. In racing-speak - "lean is mean"...but you can melt important things like valves or pistons if you're too lean and too hot. Goose it and throw some more fuel at it, and it'll cool it off a bit.
I agree with all that you say...except that my belief is that "lean burns hot" is only related to gas engines.

EGT is directly related to piston velocity and BTUs released by the fuel. More fuel and lower RPMs create higher temps. When the fuel is burned on the power stroke, the longer the flame stays in the combustion chamber, the hotter it gets. Higher RPMs allow the hot gasses to leave quickly and fresh cold air to enter.

Higher RPMs also create more power at a lower torque so the work is done with less engine and transmission stress.

The worst case scenario for high EGT is wide open throttle under a load that is too great to sustain while at a lower RPM (aka "Lugging"). Most automatics will downshift...but, as mentioned, the ECO programming could possibly delay or prevent downshifting long enough to experience very high EGTs. It only takes a second for EGT to rise, and damage can occur after 15 seconds. Metal parts begin to anneal and change properties (melt or weaken) with higher temps.

As has been mentioned, tow smart. Get an ODBII interface that reads EGT and drive within the limits by manually downshifting or slowing down if necessary. For our automatics, watch the trans temp on the EVIC as well.

Hopefully, the VM3.0 de-fuels itself on high EGT but until someone tows heavy and confirms that it is impossible to hit high EGTs for extended periods, better safe than sorry!

BTW, all if this is standard stuff for the diesel towing and racing crowd. We are just now discussing it here. Its no big deal.
 
#41 ·
A few people are mentioning other vehicles which don't change in temp when they hit a hill.

There ain't no such animal. All you are seeing is a "dumbed down gauge", like on my wife's Hyundai i30 diesel.
Working hard, Aircon on, climbing a mountain range on a hot summer day, gauge sits half way.
Winter's day, descending the same range, gauge sits half way. Total baloney.
Many modern cars are like that, really no better than the old temp light cars once had.

A good friend's Landcruiser v8 diesel is like that- he was always boasting how the "Toyota has a proper cooling system", yet with an infra-red temp scanner I've proven the total outright lie which is the coolant temp gauge. Yes, he was shocked to see the real truth, after we towed up the Toowoomba range. I got him to pull over and pop the bonnet, and hey, guess what, the coolant temp was about 112 degrees Celsius, (233 F), not the story the gauge was telling!
Anyway, that's why we have pressurised cooling systems and high tech coolants, to raise the boiling point.

At least on our JGC diesels, we have a gauge which seems to tell the truth.

Has anybody had one actually overheat?
Not that I know of yet.

Mine is only brand new, no towing yet, but will certainly be watching it with interest rather than alarm!

Cya



Sent from my iPad using JeepGarage
 
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