Has the STC fitting been replaced? It is definitely high pressure oil related. ICP needs a minimum of 500psi to start.

 

Just had my STC fitting replaced on my 2006 for the same "hot no start" issue after they went through the dummy plugs and stand pipes and and IPR valve. Notice where the two pieces come together there is an uneven fit and my understanding is this is what caused my pressure change ( not a diesel mechanic by any means but I'm starting school for it in a couple months) I have have had no issues sense this was replaced sense then.

 

I'm not sure I will check with the owner about that I know it has had a lot of work done to it thanks for the reply

 

He said the high pressure oil pump was replaced with one that is "bulletproofed" so I would assume that the stc fitting was replaced also but not sure how to check

 

The 05 and later HPOP's are not that failure prone and the culprit is usually the original STC fittings. The old ones are two piece and the replacements are one piece. The only way to tell is to pull the pump cover. The other issue is the stand pipes and dummy plugs which also come in an upgraded version. There is a procedure to pressurize the system with air and listen for the air leak. If it is coming from the one or both of the valve covers then it is stand pipes or dummy plugs. You tube has several how to videos on the 6.0 HPOP system. The STC fitting in mine failed at 88k miles. At the time I was not sure of the actual culprit and replaced the STC fitting as well as the stand pipes and dummy plugs.

 

Is it possible It is the ipr itself it is a napa aftermarket

 

From the first post I would say doubtful. Somewhere in the system is a leak and without a test it could be hard to find. Since hot oil flows more readily, that is why it is a hot start issue. Eventually it may get bad enough to become a no start issue.

 

So if I put air to the icp hole will that help to determine where the leak is coming from

 

It should help, you will have to determine if it is coming from under the valve covers or from under the HPOP cover.

 

I used Ford trucks for my business. I have one with 6.0 ltr engine and other one with 6.4 ltr but I've always had problems with both. I am glad I joined this forum. I have learned a lot here.

 

I have fixed this no-start-hot several times now and the solution is often a little bitty o-ring atop an injector. Feed shop air into the high pressure oil system (there are many you tube videos on how to do this) and use engine ears or a stethoscope to listen around for a leak. You can use a piece of rubber tubing if you don't have a stethoscope.

Also, if you get stranded, you can start the truck on a little whiff of ether- it will get the engine turning fast enough to build enough ICP to let it start.