I'm working on my cousins 6.0... It was running like **** so I asked him if he was having to put coolant in ever so often he said yeah... It checked the egr and it had water and the intake and egr valve were clogged...so I changed his oil cooler and egr cooler nothing is leaking and all the o rings and gaskets are sealed and all the wires are hooked in their right spot... The truck will crank and idle fine now but you put it in drive and give it the throttle it will die every time and its a little hard to get it back to where it will idle and sometimes it will die at a idle... Do u think I'm sucking air from somewhere and getting it in the fuel system?