I've got mixed thoughts but figured I'd try for some good advice. Friend is looking at a 04 cummins 184k miles, came into the shop smoking to beat ..... Anyhow they found something wrong w/#1 so they bored #1 and 6 out 20 thousandths. Re ringed and bearinged and the truck still doesn't run..
I can't see doing 2 of 6 cyls really a good thing, but what do you guys think?

 

Check the injectors for damage, fuel rail pressure and the computer. Also check for signs that dirt has been sucked into the engine.

 

I don't believe in partial overhauls. Do and do it right the first time.Now you hav e2 good cylinders and when are the next ones going? I work on airplanes and never have liked partial OH.

 

With all the smoke, I'd expect there to be a timing problem. The 2004 motors are electronic; there's probably something like a crank position sensor either bad or missing. Have they queried the computer to see if it thinks something is wrong? Excessive smoke could also be from a boost sensor malfunction, or a problem with the intake plumbing resulting in loss of boost; the smoke is from the computer supplying extra fuel to make boost.

Given the single head design of the ISB motors, only doing 2 cylinders does seem a little strange. "Boring" is even stranger, since the B-series is a wet-sleeve motor. They should have just re-sleeved. With 180K+ on the motor, I'd think that sleeve perforation might have been an issue, so all 6 should have been done, since 90+% of the work to do all 6 was already done, just to do the 2.

Doing partial rebuilds is a common practice on larger (12-14L) motors. If more than 1 or 2 cylinders does not NEED work (such as in the case of dropping an injector), the cost involved with a complete rebuild can be prohibitive. In the case of 3-head motors, you can give the needed attention to a single (or pair) of cylinders without disturbing the other 4.

On the other hand, with a single-head motor, if you do the work to get to ONE cylinder, you've done the work to get to all six, so it's sorta stupid to NOT do all six, unless you're on a shoestring budget. (as happened to me, with my single-head Detroit Series 60 -- dropped 1 liner, decided to do all 6 since 99% of the work was already done.)

-blaine

 

The B series Cummins is without a doubt, not a wet sleeved engine.

 

Yup, the B series engines are parent bore. Not wet sleeve.

 

I used to work in the cummins engine company warranty department where we fielded tech support calls for all of their warranty repairs. While the ISB does not have liners, you can bore them out and put what they call a repair sleeve in them. Typically if you are going to bore 1 cyl then you are supposed to bore all of them, however if you install a repair sleeve you can just do 1 cyl at a time.

 

Hmmm.... Indeed???

I coulda swore that they were wet-sleeve motors... maybe I've just been breathing too many diesel fumes.

-blaine

 

Nope,,, The hubby and I made that mistake on our 3408 CAT. Didn't have enough money for all 8, so we only did two, and three months later did the next two,,, every three months we did another set until we finally went through the whole engine.

Only good thing, is we got so we could whip it out in a weekend, bad thing is we bought four head and pan gasket sets.

Our shop partner asked us why we didn't just put velcro on those heads!!