How are Tundra Coolant Temps while towing

This might be a bit long winded, but I am looking for some genuine feedback from people who tow travel trailers or enclosed trailers year round in the Rockies with their 5.7L.

Backstory: I have a 2014 F150 3.5L Ecoboost with the max tow package(3.73 gears, upgraded cooling, 11,100 lb tow rating) that I bought new in February of 2015. I bought a Jayco X213(24' total length, 5500 lb GVWR) travel trailer in August of 2017. The Ecoboost pulls like an absolutely freight train, but since literally the first tow, I have had cooling issue with my F150. It seems like any time the ambient temps get over 85F, I have to pay attention to the coolant temps. I cant get the ECT's into the 240's if I am not paying attention and don't back out of the throttle.

Now, I tow in some pretty extreme conditions being from Utah and generally towing in WY, ID, and MT. My living room is at 6500' and I am often towing at 8000'+. I can be doing this on a 90-95F day, with 30mph headwinds, and 70-80 mph speed limits(I dont actually tow at 80mph, but try not to drop to far below traffic flow) while pulling 7% grades. There is a lot going on and I am asking a LOT from my truck. This is where the Ecoboost gets HOT. Normally I can manage the temperatures, but when you throw a headwind into it, the engine gets warm even on the flats. If I am towing at 55mph with a 30 mph headwind the engine is working like I was pulling at 85 mph with a giant box behind me. You get my point.

Fast forward to this weekend: I towed my travel trailer with my 2011 Lexus GX460, which has the 4.6L 1UR-FE that the Tundra used to come with. It was fairly underpowered compared to the Ecoboost, especially with the high elevation, but got the job done. What amazed me was that not once did my coolant temps hit 200F. The highest I saw over 7 hours of towing was 199.4. This included one climb from 6500' to 9500' over 6 miles, and another climb from 5000' to 8500' over 10 miles. I was not in high temperatures or strong headwinds, but I still think this was pretty solid.

I am curious how the 5.7L in the tundra does in these kind of conditions. Can I hook up my trailer and tow in a 30mph headwind without worrying about coolant temperatures? What about the transmission.

And please don't make this about bashing Ford. The ONLY problem I have with it is that it has issues keeping cool. And its not like I am climbing hills at 35mph. I can climb at 50-55mph in these above conditions but would prefer not to worry about it at all.

 

I have not really tracked ECT while towing on my Tundra but I will say, with heavy use around town the truck stayed at 190 plus or minus about 1 degree - really held well.

On the other hand, our 2019 Tahoe...the OE t-stat is rated to start opening 202F and be fully open 232F. With that said, same drive profile as I did in the Tundra, seeing high 220 temps was not uncommon whatsoever. I found that to be ridiculous so I brought it up with a dealer who addressed the issue with TAC (GM tech helpline). They found our cooling and temps to be OK per the specs of the t-stat.

FWIW my 2 cents

@mass-hole have your tried running a lower temp t-stat?

 

Not what he is talking about, did you read the subject line and the actual post at all?

ECT not ATF temps

 

Whoops,I'm so used to the trans temps on here, lol. Oh, by the way that'll be something he will run into with a new Tundra. My coolant temps according to scanguage were around 204 towing 6500 lbs in the mountains at 90 degrees.

 

One thing that is strange with the F150 is that the tstat is located at the inlet of the water pump. The tstat basically sits in the flow coming out of the radiator. It causes the ECT's to be very volatile as you adjust the throttle since its trying to keep the coolant entering the engine constant as opposed to keeping the coolant flowing too the radiator constant. Its a weird setup but I can see my coolant go from 185 to 210 in a matter of seconds because of the way it is set up.

Towing in extreme conditions it stays in the 220's usually, until I hit a hill. Then it will start to climb and I can get into the 240's if I don't let out. Truck goes into limp mode somewhere in the 250's. The truck has a tremendous amount of power and can pull any hill at 70 mph without issue, but it usually gets too hot before you get to the top.

 

Because its a 3.5L TT? I am hoping Toyota does it right and continues putting a mechanical cooling fan in it unlike Ford. I do think the electric fans they use are part of my issue.

 

Dricing in the Tahoe by myself I can do a heavy pull to merge into traffic and get my ECT to 229F (from nominal 210 OP temp) within that short time (amb temps high 80s). So I'd say you are doing OK at 220 while towing lol

Quick google search looks like a 170 t-stat is a popular upgrade on the 3.5l EcoBoost.

 

I've got an OE Motorcraft 180F tstat from the Mustang. Made no difference. The stock t-stat fully opened by ~208F so the cooler stat doesn't help in that regard. Nor did my intercooler upgrade, Setrab oil cooler or transmission cooler upgrade. Only thing I have left to try is a Mishimoto radiator.

At this point I am just trying to figure out is the Tundra would do the job or if I need to start looking at HD Pickups. The new Ford 7.3L looks really nice but not wanting to go buy a new vehicle for $45-50k if I don't have too.

My trans never gets hot though. Even on the hottest days the worst I ever see is 212. Normally 206-208. Not towing I am around 203 because its thermostatically controlled.

 

Pulling our 5k lb boat thru Texas, New Mexico, Arizona in August last year, ambient temperature 105 to 108, the highest I saw was 209 degrees. No real grades though.

Usually going 65 mph, trans in S mode, 4th or 5th gear, tow/haul button pushed.

Towing the same boat thru Phoenix up to Flagstaff, ambient temperature in the high 90's, saw about the same (209) high temp. Lots of pretty good grades going up to Flagstaff. 4th gear @ 65 mph.

Edit: Normal coolant temp seems to be right around 190. Temps are displayed on a Bully Dog tuner.

 

I pulled a max GVWR (likely over) load from IL to CA, across the mountains, in 100 degree heat, with the AC blasting, into a headwind.

Temps held at 195 on the flat regardless of speed. On hills, when the TC unlocked in lower gears and the trans started dumping heat into the radiator, temps would go up to 199 or 201. Never went over 202. I can't imagine more severe conditions to test the cooling.

 

What were you towing?

 

Towing my 6500lb tt through over grades I've never seen over 210 ect. Normal unloaded is around 195. The only time I ever saw over 210 in a tundra was in 125 degrees in Thermal CA in stop and go traffic with the AC on full blast. The ects got to 215 on that trip. It was also the loudest I’ve ever heard a mechanical fan.

 

My truck had 3 people and a dog, and a bed that was loaded full of high weight/high-density items that I couldn't ship. We were pulling a 28' travel trailer that was fully loaded--probably north of 9500 pounds.

 

From my limited time on the oil forums, I'm pretty sure 190 degrees is an absolute minimum to control moisture in the crankcase. Many vehicles run to 220-230 degrees. Perfectly safe and normal. Over 240 and I would start to worry. I realize this post is a few weeks late, but those temps aren't necessarily out of spec.

 

I think with the Ecoboost you are seeing elevated Engine Coolant Temps because of the turbos. They are cooled with the engine coolant and when towing and taxing the engine they are always under boost and generating heat that the coolant has to take away. While a N/A 5.7 V8 doesn't have the turbos dumping a lot of heat into the coolant.

 

My old boss had a 2013 ecoboost, and between it and my 2014 Tundra, his definitely felt better pulling an enclosed trailer. I'd say because the 420lb.ft. of torque is at like 2500rpm vs 401lb.ft at 3600 for the Tunny. I can't wait to test drive the all new Tundra when it comes out. In the LS 500 the 3.5 TT makes it's 442lb.ft AT 1600 RPM!! I think in the truck, it's gonna be a towing beast. Within reason.

 

Worst I’ve seen is 204.

 

Are your coolant fans working correctly? Do they go to high speed? Have you checked your fuses and wiring harness for the fans?
F-150 harness for the fans are known to fray and either blow the fuse or limit amps and therefore do not go to high speed.

 

What he said, you will know if they are on high speed sounds like a 5ft. medal blade shop fan.

 

I think the mechanical fan is why the Toyota cools so well. It can move an amazing amount of air especially if you're towing in S4 and the engine is turning 2500+ rpm. It sounds like a kenworth when the clutch sees enough heat

 

In s4 at 3500 rpm in 80 deg weather I’ve seen coolant temps drop to 180. Lol.

 

198°-200° towing 7000+ lbs, climbing to 4000' in about 10 minutes

 

TFLT just did a video on this very subject. It just come out a couple of days ago on YouTube.

 

Focus was ATF not ECT

 

At least that's what I was gathering, could be wrong.

 

I have a 2010 Tundra that I haul 30 ft tiny homes built on trailers from Orem Utah all the way to Palm Beach Florida. Had to upgrade my rear suspension for these 20K Lb trailers, and only got about 5mpg, but my coolant temp never got over 220 Fahrenheit. As long as you don't push the engine too hard (red line) you should be good. Just keep an eye on your transmission temp with a big load.