2011 F-250 6.7
H&S Mini Maxx
Fully Deleted

I need some ideas on what is going on with my tranny. I purchased my truck back in August with only 14k miles on it. It was a weekend camper hauler for the previous owner who drove very little. He bought it brand new and had it fully deleted with the mini maxx put in right away. I bought it in that current condition. Since buying it I have used it as a daily driver. Current mileage is 21k.

About 2 weeks ago I did 2 things. First, I decided to update my mini maxx from H&S's website to make it current as I was having a really firm shift from 2-3 gear. This is a know issue with my year truck due to a solenoid issue and I figured a more up to date tune might help. Second thing I did was tow for the first time since getting it. I towed an open bed car hauler with an SUV on it down the highway for about 150 miles. Prob about 7k#s. While on this trip I noticed my tranny temp go up to 235 degrees. When I reached my destination I parked the truck and stayed the night and returned back down the highway unloaded not towing anything and it still went back to 235. Trip was on the highway and is mostly flat with very few hills.

I monitor all gages religiously and know my trans has never even gotten close to 200 before. My oil and coolant were both running in their normal mid to high 190 range and everything else appeared normal about the truck. I have talked to several diesel performance shops and received multiple ideas about what it might be. All seem to be in agreement that it is not my tuner as no one else that I can find has had this issue with their mini maxx after updating.

Ideas for what is wrong range from the solenoid issue making the gears slip causing additional heat.... to my thermostat in the coolant valve having gone bad. I have had it in the local Ford dealership all week and they are completely clueless. They claim that everything they can check with their computer for flow and whatnot is functioning perfectly fine. They also claim that at 235 it is not out of spec according to Ford and that Ford doesn't consider this temperature to even be an issue or something that needs to be fixed.

I need ideas or suggestions or anything anyone has because the next step for the dealership is to start replacing things and hope they come across the problem trial and error style. it is out of warranty so the bill falls completely on me. Hoping someone has some kind of idea or knows what this may be???

 

I'm not sure if the solenoid would cause more heat, but I do know that most all deleted trucks should be run in the stock position when towing anything. What was yours set in? My tranny runs about 205* to 210* all the time while pulling my 15k camper.

 

It was in stock while towing and heats up in every setting while just running regular not towing now

 

I'm sure some of the tuned guys will come along shortly and will have much more info. Stay tuned...

 

Sure hope so cause I'm stumped and it's gonna get expensive fast

 

I'm fully deleted and run in the stock mode all the time with my H&S Mini.

I never had any tranny temps that high. Always around 205-210. I pull a 45' @ around 20k. No issues.

I did have my truck in for its 30k on Monday and they noticed a small leak from the tranny pump from what they say. The dealership dropped the tranny and replaced tranny pump and the torque converter too. The mechanics stripped some bolt on the converter so I got a new too. Other than this no issues and that was not even an issue that I didn't even know about.

Do you notice any leaks?

 

Check the tranny temp sensor. Perhaps it is bad.

 

No i have not noticed any leaks at all under the truck


and i am having them look into what the sensor will cost to replace. I need to make sure they verified the reading with an IR gun. assuming they did that already though i have no idea where else to go with this

from what they're telling me, they have never had to replace a tranny cooler which is the first thing they want to try.

I think it is a flow issue of some kind with the fluid but have no idea what would be affecting that. any opinions?

 

Can you monitor ECT 2 temps or did you take that sensor out of the loop? I would check to see if the secondary cooling system is doing its job. I usually tow with the 120hp tune and I have never seen my trans temps go over 204*.

 

would that be labeled "coolant" on my mini maxx? if so i have been monitoring that and it never goes above 199. oil is the same. if it is labeled a different sensor in the mini maxx please let me know and i will monitor it today and report back. thanks

 

No. It would be labeled ECT2. It runs around 80 to 110-115ish depending on ambient temp and workload.

 

i checked all my gages and this is not listed in the options. All original gages are still attached however so what other name might it be listed under?

 

It is the secondary cooling system you are wanting to monitor. Who's tuning are you running. For the longest, Spartan was the only tuner that required you to keep the ECT2 sensor in the loop.

 

H&S tunes. I have a million gage options just not sure which one is for the secondary cooling system from the names listed

 

Check the transmission temperature after a long cold soak. After sitting all night the transmission, EOT, and ECT should all be within a few degrees of each other. If the transmission temp is more than a couple of degrees off you may have an issue with the circuit or the sensor.