Engines are just a mechanical means of harnessing heat energy to do some work.

3.5 liters is about 213 cubic inches of displacement devided by 6 is about 35.5 cubic inches per cylinder, give or take. What it gies up in displacement it attempts to make up in turbo charge boost. Pack them cylinders tight. The turbo mashing already hot air / fuel in there under manifold pressure makes the charge even hotter, then you have a piston come up and further compress the mixture making it even hotter, and do this time after time, every revolution? Small engines have smaller surface area for water jackets full of copolant to absorb and carry the heat away to a radiator. You can have huge radiators but if the heat isn't absorbed by the coolant in the block, it can't carry it to the radiator.

That 5.4 is normally aspirated, has 8 cylinders so each is about 41 cubic inches, each is slightly bigger and is being asked to provide less power, less heat converted to work, and each compresion stroke only compresses what the intake stroke pulled in, not what a turbo could squeeze in ... and cooling spread over the water jackets of 8 larger cylinders.

Throw in 8 or 9,000 pound trailers and long long real grades in high ambient temps?

Don't surprise me a bit that the bigger engine had an easier job doing the work with less fuss. Little motors with turbos to pump them full of big gulps make big power but they can't do it as long as the big motor just loafing along. There are limits as to how hot we can run engines, limits imposed by materials, component design, lubricants, space ... and if specialty built to withstand the ordeal, any cost advantage vanishes.

I'm not down on turbos, I am a huge fan of the Buick Regal Grand National, it''ll fly, a favorite car of mine ... but a big cube v-8 with maybe less peak power normally aspirated will pull a long hot grade with a heavy load better longer.

 

This issue alone wouldn't stop me from buying an ecoboost but I do see this being a potential problem for anyone that will be towing that much weight in such extreme conditions. Everyone who keeps thinking this ecoboost motor was built by god himself need too open your eyes and realize just what is being asked from such a small displacement motor. You ever noticed all the diesel powered vehicles struggling while pulling close too their max weight rating in conditions like this? Even they struggle with overheating and extreme EGT's. Now you have this small twin turboed 6 cylinder having hot air shoved down it's throat in 100 degree temps and you don't think it's not gonna have overheating problems? Some of you really need to get your head out of the sand. 95% of potential ecoboost owners will never experience this problem but for the ones that will be towing such heavy loads up a steep long grade in 100 degree weather may be better off getting a different powerplant.

 

very true, alot of newer vehicles are coming with minimal water jackets to allow for quicker "cold start warm up periods" to minimize cold start fuel dumping to warm up.

keep us up to speed OP!

 

I wonder if they t-stat was working properly? Anyways warranty will take care of if.

 

Please don't tell me for one minute you think his situation is right or normal? Ford does extreme testing in Death Valley a year or two prior to releasing the motors. They load them up with 90% max capacity, drive the and idle them for hours on end in 110 degree temps. I guarantee you 99% of the EB trucks will pull that grade with ZERO cooling isues.

 

Update: We made a road trip from Flagstaff to Sedona today and we didn't get back in time to go to the Ford dealership. The truck performed incredible and the temp gauge didn't move at all (without trailer). Tomorrow we are headed to the Grand Canyon and then on Wednesday, I am hooking the RV (bumper pull) back up and we will be headed to a campground north of Durango. I'll give another update then and I'll try to talk to a dealership there since we will have more time. Another note: I couldn't believe how quickly it cooled down when I let off on the accelerator (thinking it has to be a t-stat problem) and it didn't smell or exhibit any signs of overheating (steam and so forth...). Again, stay tuned and I will let you know Wednesday night.

 

Great story. I love internet stories. Almost believable. Where I come from we call this "Hot Garbage"

One guy with 3 posts claims an issue then out of the wood work comes all the "internet experts".

I tow with the Ecoboost every weekend. I also have been towing in very high temps of 95+ with humidity above 50% most of the time. Engine temps are fine... also trans temps fine. Engine also just "loafs" along highway speeds and doesn't work hard at all.

 

so that's why the 18 wheelers with there turbo 6 cylinders are parked on the side of the road. there not resting there cooling off.

 

Just to clarify some of the bull**** that gets spread around this site....

Do you even know what the block looks like on a Ecoboost? Well, I can show you.

This is called a "wet sleeve" engine = Ecoboost.

 

And towing in flat land or rolling land is far different than his towing a 9K lb trailer up that grade for 5-6 miles steady followed by an equally long hard second stage as he was. Most any vehicle out there will loaf along with you in that setting.

Sure, he might have had an abnormal issue, but the way he was using it that day is the one way you will tax a cooling system the most and a twin turbo 213 cubic inch engine running on gas producing 365 hp @5500 rpm & 420 lb·ft @2500 rpm with 90% torque available @1700-5000 rpm. That's a lot of work for a motor that size for long durations without break.

And for more "hot garbage" ... the relative humidity in my basement is about 50% as well and that's with dehumidifier but that's a mute point because relative humidity means nothing when you're talking about your engine's temperature, it don't feel comfort or discomfort like you or I do. The reason we feel high humidity levels like we do is because high humidity means less sweat evaporation from our skin which makes us feel so "sticky icky", makes the air feel "heavy" to us, and we are less able to cool our body's core. Optimum humidity in your home for example is between 40 and 50 percent, while anywhere between 30 and 60 percent is perfectly acceptable and comfortable.

The point wasn't about 6 cylinders in particular, could have been a 213 cube V10 and same deal, smaller surface area and requiring more work out of each cubic inch by packing in greater charge. How long do you think an 8000 hp top fuel motor would last pulling that grade? It'ld melt down.

Those big diesel trucks are built to handle it, the motors are masive in displacement and sheer mass of the parts to withstand it, and they are running seriously high compression 'cause they are "diesels".

 

Yeah, I do .... and your point is ?????

ps .... the Ecoboost is not the only wet sleeve engine out there and it has nothing to do with the name "Ecoboost".

 

Hopefully its something easy to fix. Another reason I went with the 5.0 V8. Im sure they are all great motors, but the Ecoboost has some proving to do to make some believers. Im not attacking the eco boost, but this wont help ecoboost cause. Good luck.

 

Yeah, they'll figure it out .... and most will never see the conditions the OP posted about.

 

C'mon, tell us how you really feel about it. Just let it all out. Don't worry, I'll give you a shoulder to cry on...

 

I'm wondering if it's just due to sustained boost for an extended period of time in high heat conditions going up a grade with 9000 lbs...perfect storm.