bought an 06 6.0 f 350 4x4 dump bed cheap. seller said it was sitting for 1-2 years and would'nt start. ficm is at 48 volts fuel pressure is at 100 oil pressure builds fine, then checked compression and reading no compression in any cylinder. my mechanic says new motor or possibly both head gaskits are blown. any ideas? thanks

 

100 psi on the fuel, really?!

Let's go back one step, any way you can read data live? Does your mech have any exp on the 6.0? I would ask him point blank if he has worked on many of them before you go letting anyone tell you the motor is shot, or it's head gaskets.
It's called throwing darts at a moving target.

 

How are you checking compression?

 

he has alot of experience in ford diesels and 6 liter the compression was checked with a computer in the data port. we measured the fuel pressure several times and it did read 90 - 100

 

The only way to do a compression test is to remove the glow plugs and put a mechanical gauge.

 

I am wondering if he meant to tell you he did a contribution test, not compression test.
There is no computer that I have heard of that measures compression from the OBDII port. Maybe I am missing something.

 

No such thing, but he also told him he needs an engine ill get another person to check it out

 

ok i'll check with him on the compression check and i think we'll pull the glow plugs and check the compression and let you know

 

Fuel pressure is awful high. Sounds like the regulator spring isn't seated properly.

 

could the fuel pressure being so high prevent it from starting?

 

You can do a relative compression test with IDS. I worked on one recently that had Little to no compression. A leak down test revealed the valves were leaking. I removed the heads and there was a bunch of goo, Oily sooty wet mess that was keeping the valves from closing. A quick clean up and the heads went right back on and the truck had good compression and fired right up. I did my compression check pulling the glow plug, and the leak down the same. This was a high mileage motor that had sat for about a year.

 

I don't think that the fuel pressure being high would stop the it from starting, but I have heard of the injector o-rings being bad, and preventing a start.

But that fuel PSI does need to be addressed.

 

dr67 thank you that sounds similiar to my situation and soundslike the heads need to come off. Good story the fella i bought it from got it from a friend of his whose wife caught him cheating and took an axe to the windows , mirrors, and, headlights. got there and there are 8 slash marks in the hood goota post pics if i can figure it out. thanks fellas

 

The relative tests tells you if one or more cyl are easier to crank over than the others, if ALL of them are low then the relative test wont work. There is only a FEW things that will give 0 compression on ALL cyl, and they are rare. I myself would run away from this "mechanic".

 

If the engine DOES have low compression on all cyl when you crank over is should spin really fast and when you stop cranking the engine will keep rotating and cost to a stop. If there was some sabotage there could be contaminants in the fuel system or possible intake or exhaust plugging. Wires pulled or cut, lots of things. I would get a TRUE compression reading from one cyl and see what you really have. Pay close attention to what the first rotation reads compared to the others