2003 3500 dually 6spd manual w/ 119k miles total

I had my engine removed locally, and rebuilt by a specialist diesel rebuilder in South Houston, TX at 110k because of excessive blow-by. #1 and #6 showed some cylinder wall scoring.

They sleeved all cylinders to standard, rebuilt the head, and replaced all internal wear parts with Cummins OEM components and warranted the engine for 18mo/unlimited miles.

In the first 250mi after rebuild the engine used 3 quarts of oil. The next thousand miles it used 2.5 quarts of oil. In it's 3rd thousand after rebuild it used about 1 qt in 800mi, all with an empty truck driven normally.

I contacted the rebuilder, who said the engine may not stabilize oil consumption until 5000mi or so, and they asked me to run the engine a bit longer, preferably with a load.

I just returned from a 5500mi vacation w/ a 3500# Lance camper on top, and flat towing a 2000 pound Samurai behind.

During the trip I averaged 16mpg on fuel, and about 650mi/quart on oil. I didn't "hammer" the vehicle at all, and never even exceeded 60mph.

The oil/filter were changed at 500mi, 3000mi, and again at 7500mi after rebuild. Oil was non-synthetic Rotella except last change, which was Chevron Delo at suggestion that it might alter consumption.

To me that is excessive oil consumption, but the local Dodge dealer (not involved in the overhaul) said that Cummins says up to 700mi/quart is considered NORMAL, and is not a cause for repairs on these engines.

Obviously, after spending $10,000 total for the engine, installation, and new external components (including an Air Dog as they said the blow-by scoring could have been due to fuel contamination, though the injectors tested "like new"), I expected more than a "new" engine using a quart of oil every 650-800mi.

How would you guys approach the rebuilder? I want to be polite, but successful. Any "T's" I need to cross, or "I's" I need to dot before approaching them?

The engine runs like a Swiss watch*, fuel mileage is 23-28mpg empty, and 16mpg hauling/towing over the Rocky Mountains, so I have no "performance" beefs.

Thanks-
Bob
*Only complaint is intermittent rapping that sounds like a sticky or mis-adjusted valve-this has been since day-one after rebuild.

 

It sounds like the engine is performing well and returning very good mileage, it's just burning some oil. Did the rebuilder spec in their warranty any tolerable limits on oil consumption (i.e. 700 mi/qt like Dodge)? See any smoke from the tailpipe (other than the usual)? If so, does it happen during acceleration or deceleration, or can't tell?

I might suggest doing a leakdown test on it to see if maybe you can tell if its burning oil from the top or bottom end. My guess, since you're getting good performance, is that the bottom end is solid and it's burning oil from the top end, maybe a bad/incorrectly-installed valve seat, valve guide or something. I'd then go to them and ask them to pull and re-do the head then. If it's burning it from the bottom end, I'd be less inclined to worry about it.

 

when my turbo was giving me issues.. it was leaking oil internally and i didnt know because of how much black smoke the CR cummins blows off the line stock... never knew it was burning oil there.. and i couldnt figure it out on why my oil level was showing low every so often when i check it.. tell the turbo started to screech like a screamin meanie at 497k miles.. took it in and they said the turbo seals were shot and were consuming oil...

just fyi.. not sure if your turbo is origional or new also... could be one of your culprits..

 

I will request that they do this. Since there's smoke on start-up, another tech mentioned valve guides or seals as well.

I don't expect oil getting past the rings to destroy the engine soon, but if I do ever want to sell the truck, I know a buyer would run, not walk, away from a truck using 650mi per quart. That is real money out of my pocket, of course, and leaves a bad taste in my mouth even now.

The shop that did the R+R figures that the rebuilder won't stand behind the engine since it's running so well. I have to be ready for that, I suppose.

In 100k miles, 650 mi/qt will only cost me maybe $2000 since I wouldn't add oil if I were going to change it in a thousand miles or two if I were just down a couple of quarts, so maybe I just will have to get used to the idea I own an oil burner.

I don't know if a bad honing job will stay stable on oil consumption for the life of the engine, or get worse, or ever improve a bit.

I also wonder if that all that oil will carbonize in the piston lands, and seize the rings, eventually leading to engine failure due to broken rings/lands/scored cylinders?

Any opinions about that?

Bob

 

I've thought of the turbo myself. Since the truck had only 109k when I had the engine rebuilt, however, and it wasn't using more oil than could be explained by the blow-by alone, I (and the shop that did the install) did NOT have the turbo rebuilt when the engine was re-man'd.

I have considered pulling it and having it done (about $300-400) just to see, though do many turbos start pushing oil that soon? I hate to throw more money at it until I learn more, though the rebuild shop COULD just blame it on the turbo since I can't "prove" it isn't leaking oil at this point.

Is there an "easy" way to tell if the turbo's the source of the oil without sending it off for rebuild?

Bob

 

I'm not much help but I too would be very upset if it were my truck and I had just spent that much money

I've had every year of CTD's since 1989 thought 2002, missed 2003, had a 04 I traded for an 01' which I just sold with 216,000 miles and now have an 06'

I have never added a quart of oil between 5,000 mile changes to any CTD I have owned, even with some leaks

 

Take off the air tube from the turbo to the intercooler and see if you have residue at the turbo, oily, black, etc.

 

If I was getting 23-28mpg empty and 16mpg towing I wouldn't complain, the fuel economy is easily making up the difference in oil use.

 

But wouldn't a seal on the other side dump oil straight into the exhaust (rather into the intake side)?

When the turbo was off for engine rebuild, the intake side was clean as a whistle, BTW.

Bob

 

I hear you. When I got 28mpg empty with a quad cab dually, I was astounded. I started getting that immediately after re-build (I took the truck on a trip after 250 local miles) when the engine still should have been awfully tight, and not usually able to give its best fuel economy. Even 23mpg around town I considered exceptional. In fact, several people said I was outright lying, but it is what it is.

It isn't the cost of oil so much, but whether the oil will cause deposits around the piston rings that will eventually cause stuck or broken rings, and maybe even WORSE oil consumption.

Bob

 

sounds more like a piston ring thats upside down to me... may only be one, may be all of them... First pull intake tubing and check for oil in intake tract. If you dont see anything there, Run the engine with the intake off then Cut the engine clean and then have the injectors pulled so that the cylinders can be borescoped.

 

What do you mean "Cut the engine clean?"

What are we looking for w/ the borescope? Scored cylinders? If some rings were inverted, how would that show? Would it more likely be the oil control rings?

 

I know you think you were doing your new 10,000 dollar engine a favor keeping a light load on it and not exceeding 60 miles per hour but you were doing the exact opposite!!! If you refer to any cummins factory manual their recommended break in procedure for newly rebuilt engines is to load a trailer to maximum gvw and go tow it up and down hills!!!

 

cut then engine clean means to run it out of fuel....
When you pull the injectors, you dont want fuel dripping into the cylinders. when you borescope it, look for wet/oily residue on the pistons.... If you find it there, you know there is an issue in that cylinder.

 

I understand that, but at THIS point, with 9000mi on it, I didn't think it mattered much. The trip I just came back from (started it w/ about 3000mi on the new engine) included lots of 11,000ft passes where I loaded the engine up (6000 pounds on/behind me) pretty well on 6-8% grades for 15 minute climbs, even though I didn't exceed 60mph uphill.

When the engine was first rebuilt, I varied the load and rpm (I drove to AR just to find some hills to drive up), but I was empty. In North Texas hills are hard to come by!

Not all Cummins owners have heavy trailers and hills to climb. I've spoken to a bunch of Cummins owners hereabouts (most of whom just drive their trucks like a car, never working it at all) have not met a single one whose engine failed to break in to where it still burned any measurable oil. Maybe the factory engines are just that much better machined?

The engine installer drove my truck 250mi before I got it to "run it properly" and the thing burned 3 quarts almost immediately and was pushing considerable blue smoke even after that. It's gone from 80mi per quart to 650mi per quart, but seems to have stabilized at this consumption.

Believe it or not I tried to find load to haul when I first got it back after rebuild, but couldn't until this trip. Maybe I should have just parked it for 6mo after it was rebuilt until I had the opportunity to take the trip I just got back from?

Bob