Re&Re 1995 6.5 Engine,Rust on cylinder walls, need to rebore?

[robson]

New to this forum and expect that some of you who have torn down these engines will have some thoughts. My '95 2500 has about 300K kms, got dusted a couple of years ago so I have been looking for a used engine to do a Re&Re. The one I brought home (pulled out of a '97 with 178K kms) was supposed to be a reman but instead it sat outside for 1.5 years with no more than a tarp on it and the intake manifold off (long story). Pulled the heads off yesterday and was not surprised to see rust on the cylinder walls of #2, 5, & 7 cylinders. Heads, valves, pushrods all look good. At this point I am unsure if I should keep looking for another engine, or see if this one will clean up. This is where my limited knowledge comes into play. I could have a rebore done if everything checks out - no cracks in head, block and crank are OK, and put in new pistons and rings. Alternatively I am wondering if I pull the pistons, can I get by with just a light honing of the cylinders and new rings? I have scraped some of the rust off and the wall looks OK underneath - occasionally some discoloration. My next question, is, if this is a viable option - how best to proceed with piston removal, and honing? I will take the block and heads to a machine shop familiar with the 6.5 for inspection of the crank and possible cracks once I determine that this option will work. Otherwise I would not go the re-bore route. Thanks in advance for your assistance.

[Robyn]

WELCOME TO TDP :):):)

Get some pix of the cylinders that are rusty and post them for us to see.

A little surface rust is not a biggy, unless it has pitted the walls.

If there is severe pitting then boring and fresh pistons are in order.

Can you rotate the crank or is the thing stuck ???

If the crank will move some take some steel wool and oil and clean off the rust in the holes that need it and then wipe the cylinders clean of the crud with a rag.

Is there a noticeable ridge at the top of the cylinder ?????

Most of these engines can run a looooooooong time with near zero cylinder wear.


Exception being if the air filter has been neglected.

If you decide to remove the pistons keep in mind that the rods are not marked at the split line (cap)

Be sure to stamp them (Rod and cap) on the side facing the outside of the engine.

Also the pushrods on these engines are a one end has a hardened ball and one does not.
Hard end to the rockers and the other to the lifter.

They are marked in a couple way
1- the ROCKER end ball are may be a copper color
2- there may be a paint stripe around the rocker end of the pushrod

Installing incorrectly will result in failure.

The head bolts on these engine are a one time use "TTY" OR Torque to yield

Get us some pix

Good luck

[robson]

Hi Robyn: Thank you for your reply. I am attaching a few pics. There does not appear to be a significant ridge at the top so I would say the cylinder wear was OK. I will check on that a little more carefully when I clean up the walls. Thanks for the advice on the piston con rods. I knew about the push rods, which are stored in order and rocker ends up, and also about the single use head bolts.

I have not rotated the crank, as I wanted to deal with the rust and crud in the cylinders first so will clean them up first and I suspect the crank will turn easily.

I have noticed no pitting of the cylinder walls, only some discoloration in a couple of locations. I will inspect more closely once I clean up the cylinders with oil and steel wool.

[Robyn]

That rust is ugly.

There has been more than a little dampness in those holes.

Get the rusty crud cleaned out and see what you have.

Hate to say it, but my bet is you will find some serious etching/pitting under that crud.

Clean it up and see what shakes.

Good luck

[robson]

Thanks again Robyn.

Surprisingly, the rust comes off pretty well, and so far no pitting yet - I have noticed a little discoloration of the wall in a couple of locations - once I have it all cleaned up, and pull the pistons, I will include a few more photos. Yes, all they guy had to do was keep it inside or under cover, or leave the intake manifold on! - that would have saved it from this!