Hello friends,
I have here a 2006 6.0 with about 200k mls. It is one of many trucks that drive around here in Germany with manipulated mileage. The owner paid a very high amount of money in 3 different workshops for truck repairs (engine+drivetrain) and the truck never ran really good. Since the last workshop visit it was no longer drivable, watch the video please.
The engine has decent comp.values on cylinders 1-7, but on 8 the pressure is very low, here is a picture of the values.






I can't imagine a cylinder firing at 8psi, that would either mean the owner has been driving with only 7 cylinders all this time (but he says the truck didn't smoke before), or the last shop did something that damaged #8.
Here is a picture of #6 injector connector:




No.7:



such things can be found all over the engine :-/


why do glow pins bend?






The question is, as mentioned above, what can a workshop do wrong ( valve cover gaskets were replaced) that could have damaged #8.

 

There are two different length glow plugs for the 6.0l. I think they put in the longer ones vs the correct short ones.
This thread may help:
https://www.ford-trucks.com/forums/887249-which-glow-plugs.html

 

its a '06 truck and a '06 engine.

 

I agree with namnguye on what might have happened.

I would get an 06 glow plug and compare its length to the ones that were in it. I do not know the exact length of the new/shorter glow plug, but I can measure one a little later today.

 

The newer plugs should be shorter, so these ones couldn't had piston contact.

 

You are saying that there is no way that some one might have installed the longer ones in this engine by mistake?

 

Anything is possible with this engine. Were the 03 plugs longer or shorter? If they were longer, we have the failure for the plugs. Then too long plugs are installed.

 

The 03 plugs were 1.2mm longer.

This is out of the link namnguye posted:

"In 2004, there was a change to the glow plug:
Due to the design change of the piston, the glow plug has been made shorter by 1.2 mm. If the longer glow plugs are installed into an engine with updated pistons, glow plug to piston contact will result, ending in potential catostrophic engine failure."

 

So 03 plugs where installed
Will order the old and new version to see the difference.
But would/could this cause combustion issues?

 

At about 3:24 in one of his videos, DieselTechRon states that the 03 and early 04 glow plugs are shorter (I'll post the link later):



Note that the 04 6.0L bible (Updated coffee table book) states otherwise:





Edit - the DTR video link:


The 6.0L bible link (page 10 or 12, depending on your pdf software; picture 13):

https://www.ford-trucks.com/ford-man...ble%20Book.pdf

 

Damage done to the piston, cylinder walls, etc could cause combustion issues.

 

But only 8 is realy bad

 

I would be doing a borescope inspection on #8.

 

Early 6.0 Engine S/N 6000000 thru 6155636 requires GP: (ZD-12) 3C3Z-12A3-42AA.
Later 6.0 built after 09/22/2003 with S/N 6155637 and higher requires the GP: (ZD-13) 4C3Z-12A3-42AA.

 

Hartwig,

It definitely had the incorrect glow plugs put in. Since that was done, one question would be, was there a prior long glow plug into #8 where the tip broke off. Another question would be if, with all this work, at some point was the intake manifold removed and the possibility of one of the 8mm hex nuts dropped into an intake port. Those nuts seem to be the worst when you ask mechanics that have had that happen or examined what happened.

I watched several videos where top-end work was being done, and way too many people put the removed nuts and bolts on the top cowl using it as a parts holder. Then somewhere along the line, something drops off. Or they just fumbled the part out of their hands, and it drops next to the intake runner. When I took my engine apart before pulling the intake, I swept the area with a magnet, then borescope, then air gun to make sure nothing was dropped and hidden in that area as I felt it was such a problem. At the time, I only planned to take one head off.

Depending on how this goes and if you are asked to do a forensic analysis, I try to look at all the expensive work in the past and think about what could go wrong at each prior repair. For example, when I was having my engine installed at the Ford Dealership, we had a conversation about going through a lawsuit where one of their techs dropped a bolt, and it took 20k for the engine damage to occur. The fastener probably got embedded into the piston and stayed there for some time. It happens even at what I consider a good dealership.

That much of a loss of compression would have to be a bent valve or a cylinder wall scored. If the piston were holed, you would see a lot of blowby in the crankcase.

Considering the stiction of the injectors during the buzz test, either FICM voltage or this truck had very poor maintenance of the oil system. I'm assuming oil because I would think you would have checked FICM output voltage.

If you have a borescope that can go through the injector bore, I would take a look around. You might be able to see a scored wall without having to remove the head.

I see Mark recommended that while I was typing.