Hello All,

Going to run a compression test on my 2007 5.9 CR this weekend and was wondering if it is a good idea to remove the CP3 pump as it will not be receiving fuel during the cranking process for each of 6 cylinders?

Thank you in advance for the input.

Hello All,

Going to run a compression test on my 2007 5.9 CR this weekend and was wondering if it is a good idea to remove the CP3 pump as it will not be receiving fuel during the cranking process for each of 6 cylinders?

Thank you in advance for the input.

Your going to remove all the injectors any ways and all the high pressure tubes will be off so there is no fuel getting to the head or cylinders. I will not shoot fuel with all the lines off it will be more or less just drooling from the common rail.

Merged your two threads for good measure.

No reason to pull the CP3, just make sure that the injector lines or CP3 outlet is plugged or fuel will go everywhere.

Sorry for generating confusion with poor clarity.  My concern is the CP3 pump will not be getting any fuel while I am cranking the engine over and thus will be run dry.  Is this hard on the pump or is the time too short and the rotational speed too low to do damage?

I would cap each injector line at the rail and leave the lift pump with power. It will get fuel and be fine.  Even if you disconnect the lift pump it will be fine. 

Hello Everyone,

I finally got around to digging deeper into the oil consumption issue on the 2007 5.9 and believe the source of the problem has been found and yes it appears to be bad news as expected.  Before running a compression test I decided to scope each cylinder with an endoscope I bought.  I ran through cylinder 1 -5 and they all looked reasonable and in good shape with maybe the exception of a little scoring on Cylinder 4 and some light burning of the piston sidewalls at a few points.  While shooting video around the entire piston and cylinder walls clear evidence of honing marks remained and at this point nothing of real note.  Cylinder 6 turned out to be where the issue lies with clear evidence of piston damage and oil droplets remaining on the cylinder wall.  I have attached some pictures which show the bad news.  If there is any good news here I think it is I stopped driving it months ago and there appears to be no cylinder wall damage.  This will have to be confirmed when I pull the head.  I am hoping that a set of pistons and other associated parts will get this back on the road again but would appreciate any thoughts others might have.

 

I hope everyone can see the pictures as my opinion is they are highly informative and the live video was outstanding for checking piston and cylinder wall condition.  this will all either be confirmed or refuted when I remove the cylinder head.

Yes I think the good is you stopped driving it when you did. Well perfect time to upgrade as well.

What type of boroscope do you have> I bought a cheap harbor freigt one that doesn't take pics, and even the optics aren't as clear as yours

Edited April 17, 20169 yr by 2500ctd

I would highly recommend a piston change to the 03-04 style. If you plan to add power go with the QSB480 piston over the OEM 03 piston. 

 

This will require a injector nozzle swap, but it's worth it for the better piston design.