After many attempts to repair my '05 6.0, I finally found a solution that has worked for the past few years. I went through plenty of rebuilt injectors and blown standpipe seals, and was successful in making it run for a while when replacing those.

The last straw was when I went through several more iterations of good start; good start cold, hard start hot; no start. Each time pressure would drop below 500 when not starting.

I would take everything apart, install new standpipe seals, then replace injector seals with an alliance kit. Every time I did this, the top, internal injector seal would be worn away as it something was abrading it.

Searching through this site I found a post in the technical section that describes the issue. The ball tube o rings in the oil rail were not sealing properly and HPO was blasting outside of the nipple wearing away the seal. I had replaced the ball tube seals a couple of times but they were still leaking since the top injector seals were still wearing away in a couple of months. It only takes one seal to reduce HPO to less than 500.

The final time that I had the issue the decision was made to replace with new injectors from Injectors Direct. (about $2200 back then) Also, I replaced the ball tubes with the redesigned ones from HHC diesel and used HHC ball tube O rings. (about $400) Of course, since I was that far into the system, I replace standpipes, seals and dummy plugs.

That was 3 years ago. My grandson now has the truck and it has over 300k miles on it, knock on wood. I hope you can get this resolved as I know it's very frustrating to have a truck you can't use.

Here's the link to HHC diesel:

https://www.hhcdiesel.com/

 

Did you pressure test to find the leak source(s) each time it had low ICP?

 

Yes, every time I had a failure I air tested.

I would cycle the IPR then listen under the oil rails to hear the leak. Sometimes I couldn't pinpoint exactly where the leak was, but I could tell which side it was on. Most of the time if it was an injector top seal you could usually find that. Standpipes were a different story, mostly could just hear gurgling. I used plain shop air at about 135psi.

 

IMO, the only way to have chance identifying the small ball tube leak possibility is by making sure the seal points have a light oil covering, and look for bubbles. Too hard by sound alone. You saw evidence at the injector seals.

Anyway, good reminder on that possibility, but the FIRST key point is to test first.

 

I agree with that. Otherwise you are shooting in the dark. Here's the ball tube thread I was referencing. My clue was when the injector top seals were worn away.
When I went to HHC diesel they had the redesigned ball tubes. They are supposed to direct any "stray" HPO streams away from the top injector seal. Don't know if it's snake oil, or not. But the truck is still running...

https://www.ford-trucks.com/forums/1...ole-story.html

 

In my experience, “large” leaks with pressure via the ICP port can of course be heard when the IPR valve is closed.

But I usually see smaller, hard-to-detect leaks that only appear after a longer time in the pressure test.

I assume that the reason for this is that we cannot test at operating temperature.

This means that the IPR valve has to be closed for a longer time when going the ICP port route.

I see a risk here that the coil will burn out in the IPR valve.

That's why I take the route via the IPR port.

In German we have a saying:
many roads lead to Rome. :-)

 

Yes, agreed.
I always heeded the advice on the forum to not close the valve too long. IPR replacement is a patience tester/ swear generator.

 

Nice post. This is where the use of a 9v battery came from. It won't harm the electronics (at least not that I have ever heard).

Since the OP can only get to 30 psi when cranking, I assume the leak is large. This assumes that the ICP sensor is working properly.

 

Just thinking - all the above advice is dependent on having good "base oil" pressure and flow.

Make sure that is all in good shape (if you haven't already):

• oil filter housing should fill quickly when cranking
• oil filter housing drain valve should close completely and hold
• OEM oil filter cap and filter
• oil filter housing standpipe not damaged

And it is possible that it could even be the HPOP, they can fail even though it isn't often. That's why we test.

 

I was doing some "old post searching" and decided to bring up the OP's post in 2004 on his previous HPO system issue. Check out the last post!

https://www.ford-trucks.com/forums/1...-no-start.html

 

Sorry for the delay in replying. Thanks for bringing up last year's post. I ended up taking it to a shop - it would start in cold weather with a lot of cranking. The shop had an experienced 6.0 tech. In last year's case, the shop replaced the branch tubes. They drove it a few times and got another code - and replaced the ICP with an OEM (I had installed an aftermarket sensor and replaced the pigtail). It ran well the rest of last season and into the spring and early summer for me this year. Then, as I posted here, it did the following one day:
1.) Started up perfectly in the morning, ran beautifully 50 miles away pulling a 7500lb box trailer. Sat for a 3 hour soak in the hot sun.
2.) Exhibited an abnormal long crank, but started. Didn't run perfectly smooth, but still ran pretty well. I stopped at a convenience store before the 50 mile drive home...didn't trust it and left the truck idling while I was in the store.
3.) Made it back 30 miles, ran fairly normally, coasted to a stop for traffic. Engine died while still rolling at 10 mph. Engine would not restart after extended cranking. Vehicle was towed with my trailer. Truck would not restart the next morning when it was cooler. With fully recharged batteries, I could only muster about 37psi ICP after extended cranking.
---------------
A week ago I pulled the IPR, screen was fine. Reinstalled, no change.
--------------
Today I am going to try again. I am going to pull the oil filter cap off first, drain whatever oil is in there, and then crank the engine and see if it fills up quickly. Note - after extended cranking, the instrument cluster gauge does eventually move off 0 to the normal oil pressure position. I'd love it to be a stuck relief plunger but I have my doubts.

I reviewed my purchases. In July of 2023, I installed a new IPR valve from Accurate Diesel. Made in USA. Cost $179 at the time. At the same time, I also installed the new updated STC fitting from them as well, and installed new "updated" but non-OEM stand pipes and dummy plugs from Pure Diesel Power. They have an interesting write-up on how their design is superior to the current OEM.

If one of the ball cup seals failed, could it cause the engine to die while running, *and* present such a low ICP pressure while cranking? Or the same question if an injector top seal failed? Seems to me it really could only be a bad HPOP, STC fitting, IPR stuck open, or no base oil pressure?

Thoughts? I'll try to update later tonight or by tomorrow.

Thanks

 

Several things:

High oil temperatures can/does reduce o-ring life.

Ball tube o-ring leaks can result in oil spraying onto the top of the injector and damaging those top o-rings.

I don't know anything about the quality of the "Pure Diesel Power" standpipes.

 

I have a used IPR valve that was working when I removed it. Should I swap it? Guess I don’t have much to lose

 

If all you can get with extended cranking is truly 37 psi, then that makes the IPR valve much less of a suspect IMO.

Leaks that prevent most/all of an ICP pressure increase are typically due to:
Failed HPOP discharge fitting
Bad HPOP
Cracked Branch tubes

Maybe a catastrophically failed standpipe, but I'm only guessing on that.

Have you air tested with the valve covers removed? I mean there should be a lot of air leaking.

 

Good base oil pressure. Oil fills up filter housing even with the valve releases pretty quick. After 40 seconds of steady cranking, I get to about 32 psi ICP. I’m out of time again today, but maybe I’ll pull the rocker covers tomorrow and re-check standpipes and dummy plugs. I don’t have the air tester yet.