Heat Exchanger by Fuel Tank?

[mcmonroe]

Would someone explain to me the function of the heat exchanger that is back by the fuel tank on a 2004 LLY?

As best I can tell it appears to be some sort of fuel radiator but I dont have a clue what its function is.

Many thanks,

Mark Monroe
2004.5 LLY D/A

[01max]

it cools the fuel going BACK into the tank. because of the high fuel pressures that the injectors use it builds a lot of heat in the fuel system.

[More Power]

Something on the order of 50-70% of the fuel arriving at the engine compartment is eventually returned to the fuel tank - after being run through the fuel cooler. Aside from removing heat from the FICM (fuel injection control module), the returning fuel also removes heat from the injectors and high pressure pump.

I've thought that the fuel supply and return lines might be better insulated where they run along side the transmission and engine (have a look the next time you're under the truck). The close proximity of the lines to the trans/eng probably helps in winter, but can't help during high summer ambient temps.

MP