Compression or what?

[widman]

I brought a 2003 F550 6.0 to Bolivia 2 years ago with 99,000 miles on it. After about 1000 miles it died (Sept, 2007). Would start and die. It was towed home where a local shop tried to diagnose it with their scanner and could not determine the cause. The error codes were engine speed sensor and something else. I towed it to Ford and they got no errors, no current. They said to replace the computer and pcm. I towed it to another mechanic who found a loose wire and mud in the fuel system. He cleaned the tanks and lines. I bought a new fuel pump and relief valve (in the filter). He could get it running, but it would not idle or run steady at any rpm. He cleaned the injectors, but no improvement.
I finally towed it to another shop 8 months ago. He kept getting injector codes, cleaned them and had me import a set of o-rings. Finally he gave up.
A month ago I towed it to another shop. At first he had several error codes, but now says there are no error codes with his scanner or with the Snap-on he borrowed. He says the problem is there is no compression. I went over today to watch a compression test, and he didn't have the gauge. That he towed it to start it and there was no resistance in the engine when he let out the clutch. That it just turned over easily.

I sent him out to borrow a compression tester, and tomorrow we will run the compression on each cylinder and hopefully have some answer.

The question I have for the moment: Is there anything in this engine that relieves compression in any conditions? Or if there really is no compression, is it possible that the rings got stuck or something? What else?

[fordboyyfm]

either its because it hasnt run for ever and the piston rings lost some tension from doing all that sitting and the cylinder walls are dried up. or it could be carbon in the intake valves which i would bet is your problem all along. but do the test, misting some water in the intake may loosen it up while your cranking it over.

[widman]

Today we ran the compression check. Obviously we couldn’t run it hot as the engine doesn’t run, and on the right bank the adapter they made was too long to fit.
The left bank gave me 280 psi on the first try, and after adding some oil to the cylinders we ended up with between 380 and 500 psi (depending on how much oil).
I found out that the 3rd mechanic that worked on it used gasoline to start it when it still had fuel line/injector problems, and it started and died each time. So I’m thinking that the gasoline dried out any oil on the walls and rings, causing things to stick in the year or so it has set (very humid climate).
So right now I’ve filled the cylinders to the brim with 5W-30 to try to penetrate whatever might be sticking, figuring tomorrow we can push out the extra with the starter and try again.
We are running various electrical tests tonight anyway just to make sure.
Any other thoughts?

[Ljutic SS]

If you put that much oil in each cylinder, even with all the glowplugs removed you could possibly do major engine damage by hydrolocking. The speed of the piston while trying to crank would never be able to move that much oil while rolling over to TDC.