Rebuild???
 

I'm at 255,000 miles. I've got more oil coming out this truck tah I know what to do with. I'm thinking of taking it in to CUmmins for a "cheap" rebuild, if it's possible and I can afford it. Seems like I'm getting alot from my blowdown line. I also seem to have a hard time keeping valva cover gaskets dry. Replaced them, back 2 still leak. Any thoughts or suggestions? What's a rebuild cost from Cummins?

Thanks,
J

I would take it to Cummins , I dont think you need a rebuild , but have it dynoed and check blowby , probably have a turbo creating all that blowby , the engine itself is really a low mileage .

I am going to try to set up a time w/ Cummins sometime next week for them to dyno and check blowby on it.
Thanks,
J

Hiya Duke! (and everyone else here!)

I'm a new member to this site, but I think I can chip in on this one...

Duke, about your blow by tube. If it's a "PUFF PUFF PUFF" flow of air, that would be more indicative of gases getting past the piston rings. I don't think there is anything "cheap" on a diesel rebuild, unless you can do the work yourself. I just had Cummins give me an estimate on a re-ring and piston job; cost for parts alone was about $600.00 per hole. A reman engine (with fuel pump) was approaching $10,000 plus labour to install.

On the other hand, if it's a steady stream of air, I might be inclined to look closer at the turbo...this is what is happening on our truck, and the speculation is that the gases are getting past the turbo seals and into the crankcase through the oil return line. A rebuilt turbo isn't too bad, maybe $900-$1200.00 CDN if you do the install yourself.

One last thing. Our truck was spraying oil by the gallon out of the BB tube when we got on the freeway and had the rpm up. Believe it or not, there have been cases where a BB tube that hung too low would act as a vacuum cleaner on the crankcase! The low pressure rush of air running underneath the truck would pass over the tube, and "help" oil get out (this advice was from Cummins themselves).

Last week, we cut the BB tube right up by the oil pan / block mating surface, and so far, almost no oil has spit out...so far. This week we're gonna get on the freeway and really hammer the throttle (builds up crankcase pressure) to see what happens.

Anyways, just to let y'all know, I belong to a couple of other forums, and I'm ALWAYS impressed by the sharing of knowledge that occurs with Cummins owners!

Now, aren't forums like this a great example of what the internet should really be all about?!?

von Trapp, that's a great first post!

Duke, if it does turn out to be the engine, you can get a reman long block (just the engine, no turbo or fuel system) for around $4,500. There are also good used engines out there in the $1,500 to $3,000 range. I would not bother with having an "in frame" rebuild done, this isn't like a linered engine where you replace the liners and the rings and everything's good as new.

von Trapp & wanna,
Thanks for the input. I spent quite a bit of time undeneath the ole' girl this weekend. Part of my problem was a bad drain plug o-ring, but I knew about that. Looking close and studying, I'm pretty sure that most of my oil is coming from front main and just blowing back from there all the dang place. I'm gonna' try to get it changed this coming weekend. Any advice/concerns I should know??
Thanks guys,
J

I assume your KDP is already fixed? No cracks on the timing cover or leaks running down the sides / front of the motor? Also, check your pan bolts too...not common, but they can "weep" and allow oil to migrate down/across the pan to parts unknown.

But before you fix anything, it's still worth your time and the few bucks it costs to pressure wash and/or brakekleen the underside and engine...get rid of all the oil / grime buildup.

Believe me, air flow can do funny things with oil, and hide the real source or a leak. Much easier to track with no grime! :D

Nope, KDP still alive....Kinda hated to ask anybody to work on it till I get it cleaned up. Yeah, I've pressure washed it. Pretty sure it's front main. Also a couple of vaalve covers. I'm looking forward to getting it cleaned up.
Thanks for all the input. Don't think it'll be too much of a problem to get the front seal changed out. I plan to get it this weekend.
I'll let ya'll know how it turns out.
J

Good luck!

Make sure you post a follow up how easy / difficult the change was, special tools used, tricks etc.

If you pull the front cover to install a front seal - that is the perfect time to install a tab on that KDP. Just a reminder.

Been there done that club....IF it becomes a O.H. issue do not do the inframe thing under NO circumstances as the are no liners in these eng. and the oil cooling tubes that are made out of plastic will get broke (if some are not allready)
2- the block has to be decked for new pistons as the oversize are not graded
3 -the bore to centerline is typically off quite a bit and this is a good time to correct it.
ballance it while there and the eng will be better then the new ones. BTDT
Ask "haulin in dixie" as we both did it all thoe he has got the record for how many times.
pm me if you need more ans.

Hmmm.....someone talk to me about this turbo causing the blowby ??

I have a steady stream, and the home made blow by test says it is almost 3x normal.

I have been thinking it was either the head gasket or rings, or maybe both. but now, I'm not so sure.

On a rebuild on these blocks, can they be just bored over .030" or whatever needed like a regular gasser engine? Or is resleeving required?

bad seal between the vaccum pump and power sterring pump can get everything oily underneath.

plow, it's not oil leaks...it's smoke. I fixed the p/s & v/p leaks, no more oil covered engine now, but the smoke can at times be embarassing.

the truck doesn't use oil either