My truck is leaking diesel from somewhere and i can't figure it out. Its about to drive me insane! A few weeks ago when i got the oil changed i guess they decided to check my fuel filter? Well they didnt put it on tight, either that or it backed off on its own. But it was leaking diesel everywhere through that. So i cleaned it up and tightened it. But its still leaking. I power washed all underneath the truck and parts of the engine where it leaked but its all back again. Its running down the back of the motor somewhere. But the front axle and and stuff is all full of diesel again. Where could it be coming from? I cant see it leaking anywhere when its running or anything like that. But when i turn it off it drips down the back of the engine. Any suggestions as to where it could be coming from? And when it leaks its not just a little bit, its probably a cup or 2 full on the ground.