My friend has an 05 6.0. He's got a miss at all temps while he's driving, i figured it was his FICM going bad so i checked the voltage on it and it read 20V while the glow plugs were on and jumped right up to 48V when they shut off, so that wasn't it. I told him to try some rev x to clean out his HPO system and injectors and he said the engine is still missing, so i dug a little deeper. when you roll the key over to KOEO and the fuel pump turns on it starts to make this wierd whinning noise and then the pump will shut off and sound liek there's air bubbling inside of it and then you can hear air bubble out of the fuel tank?:dunno: Does anyone know what this sound could be or if it has anything to do with his miss? he says the truck still pulls like a champ and works hard.