Thanks-makes perfect sense. Any residue is from the top or bottom end then.

Bob

 

I noticed you are not mentioning excessive blow-by on the reman. This would indicate the compression rings are sealing. Since the oil consumption did drop as the engine broke in, I think the problem is related to the oil control rings. They may be installed incorrectly, ill-fitting, or damaged by rough handling. The consumption got better because the oil rings sealed better as they broke in. The oil rings could even be the wrong part for the application.
Ted

 

Yes, zero blow-by (the typical pulsations w/ the oil filler cap removed, but no outward flow, and no smoke at all-just clean air moving in/out).

Now that I have 9000mi on the engine, and consumption has stabilized at 1 qt per 800mi no load, and 650miles working pretty hard, I suspect that I will see little if any gains from here on?

Working an engine hard seats the compression rings more than it seats the oil control rings as I understand, so if the top couple rings seated OK, hopefully I didn't mistreat the engine by not loading it up. Don't the oil control rings work pretty much by their spring tension?

I don't know if the Cummins uses one-piece or 3 piece oil rings.

Bob

 

Yes the oil rings work by spring tension without the help of cylinder pressure. This would mean working the engine would not push the rings against the cylinder more tightly to help them wear in and conform to the cylinder walls. If your problem was turbo or valve related the oil consumption would not have improved.
Ted

 

sorry i didn't realize the engine was seated in before you recieved delivery.
A quart every 800 miles is excessive consumption for one of these engines after a complete rebuild. My daughters 2001 is at 1,500 a quart at the 225,000 mile mark pulling a 31 foot horse trailer, my 2003 burns a quart every 7,500 miles or so at the 160,000 mile mark which is pretty close to where it was at when i bought it at 23,000.

 

Well, I didn't do the first 250 or so miles, anyway.

The shop that did the R+R (but not the overhaul) is a one-man Cummins specialist shop widely respected hereabouts, so hopefully he didn't screw it up.

No matter; I am not a really happy camper regardless. Leaves a bad taste in my mouth every time I use the truck, though that's irrational I suppose.

I just want to approach the rebuilder from the RIGHT angle w/ the most logical argument I can as I am sure I get one shot at convincing him he should do something.

The other alternative is small-claims court, but that's limited to $2500 I think, and that would just be enough to pay for another R+R, but I suppose then I could get the cylinders re-honed and new rings installed on my new (9000mi) pistons for a reasonable sum.

I've always done my own engine rebuilds (10 or 15 probably), but never a diesel, so I'd have a specialist shop do the honing.

Normally, in this situation, I'd pull the pistons off the crank in place (not possible w/ the 2wd as I understand the oil pan cannot be removed in place except for the 4wd), put lots of clean rags at the bottom of the cylinder bores (to keep crap off the crank journals) and hone the cylinders with WD-40 on the stones, carefully remove the rags and residue, clean the bores THOROUGHLY, and install the new rings. I've done that at least 10 times with flawless results.

Bob

 

If it was started with Reg motor oil it would had been better off. That way the rings could had seated in! Try ruining some good oil NOT Synthetic ! Try ruining it 6000 miles and see if that helps. == GOOD LUCK ==

 

The engine has not seen a drop of synthetic oil since forever.

Personally, I'd have broken it in on non-detergent oil, but that would have voided the warranty.

Bob

 

All I can say it I understand how you feel..

 

A quality shop will run tests on the engine to determine the leak. Given its easier on a gas engine, but there are leak down tests, compression tests, pulling the valve cover and looking at seals. The person that rebuild the head could have boogered up seals, perhaps the turbo is leaking. Either way it is excessive, but the question is now, will they take the time to find the leak.

 

My guess would be that when the engine was first rebuilt, most of the oil consumption was from the rings, with some from the turbo. Now the rings have seated and the turbo is still leaking a small amount, which is his current oil consumption.

 

I have/am in the same boat as yourself but with the VW 1.6td I had rebuilt for my samurai.

Excessive white(ish) blue/black smoke on cold start (24 hours or more of sitting) oil consumption, coolant consumption, oil leaks from the headgasket and rear main area (don't think it was the rear main seal itself)

Earlier this summer I dragged the samurai behind the truck going camping. I dusted the motor to the point of not quite running right, got it stinking hot climbing a mountain with four people in it and a bunch of gear, and wound the living snot out of it...

My oil leaks seem to have sealed themselves up. Could be a combination of dirt and heat that did that, the dust allowed me to see where the coolant was leaking from. Tightened that clamp. The smoke isn't nearly as bad on startup as it was.


In no way am I telling you to abuse your engine like I did mine but getting it hot and working it hard would be your best bet. I still don't think it has had enough time to break in even at 9000 miles. You are in some pretty flat country around there.

An alternative would be a dyno at a cummins dealership. They will strap it down hook up a bunch of hoses and run the snot out of it (while loading the dyno) to check the health of your engine. I had that done on a '93 that the dealer had installed the wrong air filter on...