I have a 2006 6.0 that has the common no-start when hot problem. The truck recently had the headgaskets replaced, egr
cooler, oil rail nipples cup seals, and all the associated gaskets with the head gasket. The truck was fine right after the head gasket replacement and didn’t have a hot start problem until about 200 miles afterward. I replaced the IPR
since some extra air sounded like it was bypassing past it and the icp
for oil contamination and it didn’t help. Air tested for an extended time cold and didn’t get anything until the truck ran to operating temp.
Found a leak at injector #1 on the passenger side bank, pulled the rail and replaced the injector seals on the whole bank isolated the oil rail on the side and tested it with 130# of shop air with no leaks. Put it all back together and still no start when hot except now the leaks was on the driver side🙄 Replaced those injector seals air tested and no leaks put the truck back together and still no start. For the record I’ve isolated the branch tubes and hpop
and there’s no leaks there. Fast forward to today I made an air fitting to test each injector seals and I’ve found 3 that have significant amounts of air coming out of the vents. Does that mean the spool valve has failed?