Siciliansteel

I have a 2014 F150 4X4 XLT with the max tow package. Bought it new in November 2014. While towing my bumper pull RV trailer up a 6% grade (which is 7 miles long), the engine gets hot and powers down to what the dealer calls lim mode. I don't understand this and don't think it's a common issue. Has anyone had experience with this? I live in Arizona and it gets hot here but this never happened with my 2004 F150 pulling the same trailer up the same hills with a 5.4 triton motor. The trailer fully loaded is around 6500lbs. Ideas? Thoughts? My idea is to manufacture a mist system, 12 volt pump, and mount it on the inside of the grill. Use a momentary on switch and mist the radiator when it gets hot. But I'd rather not if there is a fix for the problem that Ford can do.

winchested

Cooler thermostat may help cool you down quicker.

Tothemax

Did the dealership give you any ideas or look it over? You should not be overheating.

Do you have the right proportion of coolant and water in the system? Is your fan coming on? Are you using AC while towing? Do you have a tuner?

Don't install a mister. You paid good money for that truck, no need to cobble it together.

Siciliansteel

Dealership said that I need to bring it in immediately after the event or by key turns, the code clears itself?? Don't know if that's true. I have never messed with the coolant or the thermostat. Coolant level is full and orange, and I did take it in to have them check it out, so I assume that they looked at the thermostat and the coolant. Fan comes on with A/C working. I do not have a tuner. And yes when it's 115 degrees outside and I am towing, I use the A/C. It was mentioned by the dealer to use premium fuel when towing. What does that do? I know it costs more. Funny thing is, with my 2004 F150 with the 5.4 triton and the A/C on, it never got hot while towing the same trailer, albeit it didn't get up the hills as fast.

bnorth

That hill shouldn't be giving you issues with the max tow package unless you are trying to pull it at like 80+mph. I would say you have an underlying issue. Check coolant for level and air locks as well as make sure the fan is functioning properly and the rad is not clogged by dirt or some other obstruction.

Martian

I'm thinking your cooling system is janky. How many miles do you have? Did you get a code of any kind? If you did, you don't have to necessarily take it to a dealer to get it read... anyone with a scanner can pull it.

mhamershock

Search my threads. I've had this issue before with my 2011. Various problems and solutions, and the problem has caused other problems (warped exhaust manifolds for one). Hope you have the extended warranty. You are gonna need it.

Mike

Tothemax

As mentioned you can have anyone (parts stores) scan for codes, not just the dealership. I would go pull the hill and have it scanned asap.

I doubt the dealership would check the thermostat, coolant level probably. You can buy a coolant tester and see what the % is at.

Premium fuel is recommended for towing. More octane = more power which makes your motor work not as hard.

What speed are you trying to tow at? Are you in Drive or tow haul mode?

joedotmac

You and I both share the same configuration truck, Ecoboost with MaxTow. MaxTow comes with an upgraded radiator.

Limp mode is a protection state, there's a serious reduction in power, less HP, less boost. This mode is to protect the engine from a problem causing a larger catastrophic failure.

Does the issue occur up the hill with your trailer with any ambient temperature or only a temperature exceeding X degrees? What is the weight of your trailer?

The higher octane is suggested to avoid detonation. There's no additional power in high octane fuel. There's been circumstantial information passed around that the truck can if it observes higher octane fuel change the tune slightly to provide 10 extra HP. You make of that whatever you want. The additional octane raises the ignition or flash temperature of the fuel. As an engine load is maintained (towing a load up a long hill) everything becomes heat soaked. This includes the block and cylinders. This drives up cylinder temperature. If the cylinder temperature becomes enough, fuel injected into the cylinder will pre-ignite before the ignition sequence, the piston hasn't reached TDC and thus there are opposing forces. This if serious enough can cause a catastrophic engine issue.

How long into your climb does the issue arise? Can you monitor your coolant temperature? Not sure if there's a way to change the IP to display the coolant temperature.

I would like to understand what factors will engage limp mode. Can a singular metric like coolant temp exceeding X degrees trigger limp mode?

Andy13186

higher octane allows for more timing I believe, which is how it makes more power.

on an ecoboost id definitely use 93 octane if available. although im not sure if its required i would still use it on any boosted vehicle. Personally i use only 93 octane on my 5.0 too and I have a 93 octane tune.