Fault Code: 482 PID: P094 SPN: 94 FMI:

[tbrink54]

Fuel is overheating, and we get this code when it does. Code 94/482 After sitting all night take off, Trucks gets 7.5 mpgs as the day rolls on the fuel mileage drops to 4.5-5 Then during a full pull up a hill it will De-rate. untill the the fuel cools back down. If the tanks are full it takes longer for the fuel economy to start to drop. Last night the fuel overheated with the truck just idling after about 3 hours. (low on Fuel) Code came on. (Alternator on the APU went out!!) Normally don't idle the truck.

Engine Coolant and Oil Temp is Normal.

Truck is a 2012 386 Pete ISX 400, It has 750 on the clock, I have done a cylinder balance test it will Idle on 1 cylinder, All cylinders. We put a longer fuel liter on it and it seem to help. (Take longer to over heat). I change the oil every 18K Last Oil Sample was Normal. Change the fuel Sep every oil change and the High Pressure Fuel filter every other. I run 1 Gallon of Gear oil every Oil change, and I put a gallons of Trans fluid in the tanks every Oil change, I have 5 of these trucks, All Identical. No other truck has this problem. It starts right up. It will Drag 80K up a Mountain in 9th with out too much trouble. (when fuel is FULL) Map Sensor has been replaced and We clean it regularly.

[Nilao]

I'm sure rawze will respond on this later with a more detailed write up but my understanding is the trans fluid in the fuel is a huge mistake on these new engines. There are multiple things that make it a bad practice. One is the tolerances of the injectors were never meant to have a fluid other than fuel run through them. Another is trans fluid produces ash which plugs up the dpf. I'm sure there are other reasons but if you must run an additive, ashless 2 stroke oil or diesel kleen are the only two I've seen recommended in here.

[tbrink54]

I will be interested to hear thoughts on Trans Fluid, I've been using it for years in my trucks and tractors. Thanks for your input.

[Rawze]

(08-16-2017 )tbrink54 Wrote:  I will be interested to hear thoughts on Trans Fluid, I've been using it for years in my trucks and tractors. Thanks for your input.

Just because you have been using it for years does it means it is the correct thing to do by any means...

What you are doing is both helpful AND harmful at the same time actually. I did some research on this a few years ago in detail and for the life of me I can't find the scientific papers on it at the moment but basically this is what was found when it was tested as an additive in the fuel system...

"ATF (Automatic Transmission fluid), otherwise knows as 'Dextron' is actually NOT a very good product to run in your fuel tanks. Although it sometimes helps to soften old seals in the fuel system, they can become too soft over time, deteriorate, and fail. Dextron ATF does in fact help a bit with lubricating the fuel pump and other metal components themselves, however once it enters the cylinders, the whole ball game changes. When burned in the combustion chamber, it produces high amounts of ethylene, produces small amounts of ash residue, and abrasive crystallization occurs, threatening long term piston and cylinder wall lifespan. That certainly is NOT good for your pistons and liners.

Besides the increased wear, the fluid is RED in color, and the D.O.T., if they see red fuel, are going to think you are using farm fuel and you can incur some pretty hefty fines for it. It sometimes has been known to help clean slightly dirty injectors a bit but there are other, more effective products for this. Diesel Kleen, or something similar seems to be a better product for assisting in cleaning injectors.
" -- Reference-- http://rawze.com/forums/showthread.php?t...622#pid622


Your welcome to piss it away as speculation, but I did research it heavily before making such a statement. Personally, I would not do it for the exact reasons stated above.

Everybody is looking for that magic "quick fix" for everything, but there simply is not one. I have seen dextron used in fuel and oil systems alike and after long term use, even in small quantities, it over-softens seals and provides little to no long term reduction in wear vs the damage it causes otherwise with those fuel system seals and components + extra cylinder wear. Lastly, the others are right about the increased ash going into to the exhaust system components too. It certainly makes the filters clog more rapidly. Take it or leave it, who am I but someone who spent the better part of 2 months trying to find actual scientific data on different additives instead of the same repeated bull$sit and advertisements you see on a hundred truck and car forums while people argued away their opinions. -- it is another one of those "Bad Informations" that spread like a virus.

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The most common causes of hydraulic fluids of any kind (fuel included) to overheat in a properly designed system is a LEAK under high compression/pressure. A leak is not always seen, but can be also a leak that returns to the fuel tank instead of outside onto the ground. That type of leak would be called an "internal leak".

Do a leak-down test of the fuel system and see if it passes. Here is what you should be looking for...