Been chasing issues on 04 6.0 that is now hydrolocked with diesel on the back two cylinders(truck had diesel in oil when I bought it). I just wanted to ask about this because I thought I had read somewhere about injector cups most commonly having issues on the rear cylinders, but now I haven't found anything saying such a thing. I probably just clipped an o-ring when I replaced the seals on the drivers side rear and there is a separate issue on the passenger side, but I was hoping someone might have some insight on only being the rear cylinders? Thanks

 

A bad injector can do the same thing, also an injector that is just loose can do it also. the worst case is a cracked head. check the orings and see if anything is evident, also if you find a loose one that is an issue too.

 

I just tore into the drivers side again. What I've found is that it was not loose, but the lower o-ring was slightly discolored. Going to try reseating it with all new seals, if it bypasses again I'll be buying a camera to see if I can spot a cracked injector cup.

I found what I had read previously, it was actually regarding injector hold downs(7th post down) Injector cups or cracked head? - Ford Powerstroke Diesel Forum I will say I have an early 04 truck with a late 04 engine, though I have no knowledge of whether the injectors were swapped from engine to engine. I'm not sure what the two different styles of hold down look like but all of mine seem to be fairly squared, but I didn't see anywhere on the head it interfered.

 

The injector hold downs changed in mid 06, 03 to mid 06 are the same.Anytime I pull a suspect injector on paSS SIDE OR DRIVERS SIDE I ALWAYS MOVE THEM TO THE #2 and #4 position on the drivers side as they are the easiest to get to in the future. The white oring will have some discoloration after time, kind of brown staining kind of look, that is normal. Always make sure you put a little oil on the orings before you install the injector.

Just a note, when you pull an injector the fuel in the internal fuel rail, that is a machined in the head. will go down into the cylinder and can cause a hydrolock unless you use some air to get the fuel out of there. One way to keep this from happening is to loosen the banjo bolt on front of the head and then loosen the fuel filter cap to let all the fuel out of the system first.

 

I did the "balloon test" on the truck regarding compression bypassing into the return lines, and neither side pulses, in fact the passenger side sucks down, whether there's any glow plugs installed or not O_O