5.9 Cummins piston ring problems?

[Dixon M]

So I bought a new step van on the freightliner chassis this year I noticed it had some blowby and a rear main seal leak with 250,000 miles on it. My plan was to replace the rear main seal and run it for a year or two and rebuild the motor or swap it out for a lowerer mileage motor. I had the truck painted and with 1300 miles on my new to me truck it started knocking I tried to narrow it down to one cylinder but it seem to alway have the knock so I pulled the cylinder head found piston #6 had ate the ring. Pulled the motor out and disassembled found #1 and #3 cylinder had a broken top ring also. #6 bore will need to be sleeved and #1 and #3 bores look ok but you can feel the rings were fluttering at the top of the bore and the pistons took a little beating on the ring land as well. So my plan is to bore it .020 over and sleeve #6 all new pistons, rings, bearings, have the cylinder head done, and 6 brand new injectors. On a side note all the bearings inside the motor looked great camshaft bearings seem to have the most wear. the rest looked new. So if any one is looking at one of these common rail engines and notice some blowby do your self a solid have a compression test done or at least run an oil sample before you by it. I will try and get some photos up if anyone wants to see the damage.

 

[Booyah45828]

I'd like to see the damage.

The only time I've seen diesel engine rings break is when someone used ether to start it.

 

[Dixon M]

I have seen them break when the ring end gap is to tight and under boost or nitrous on performance engines the rings will expand and butt together and break. But either way doing a google search I found a lot of this era motor with the ring issue and it seems most common on #6 and #1 cylinders. I thought with this being just a 185hp model and the dodge trucks with the basic same engine is 305hp it would last forever but I was wrong. I will also keep tabs of the cost and let people know about how much it cost for parts and machine work.

 

[Dixon M]

Something I forgot to mention was this motor was not hard to start and never smoked out the tailpipe drove as you would expect going down the road and was getting 11-12 mpg on the few tanks i filled it with.

 

[Dixon M]

Here are some photos

 

[EastCoastCB]

Nice lookin stepvan. Sorry to hear bout your ring situation.

I haven't looked at Cummins stuff for sale but I know if I had that problem with my engine I'd probably just look for a running used unit to swap. Maybe get a higher hp rated one complete with ecm.

 

[Booyah45828]

I have seen them break when the ring end gap is to tight and under boost or nitrous on performance engines the rings will expand and butt together and break. But either way doing a google search I found a lot of this era motor with the ring issue and it seems most common on #6 and #1 cylinders. I thought with this being just a 185hp model and the dodge trucks with the basic same engine is 305hp it would last forever but I was wrong. I will also keep tabs of the cost and let people know about how much it cost for parts and machine work.

That's with gas engines. When you take a stock 200 hp small block chevy and throw a bunch of boost or nitrous at it, the rings heat up and expand farther then normal. When that happens, they butt together like you said.

Diesel engines typically don't run that tight of a ring gap, so they don't suffer this kind of problem.

What you have shown is typical of an engine started with too much ether. The top ring lands are busted out towards the crown, there are pits at the top of the cylinder bore, and you have busted rings.

The only other times I've seen broken rings is when the engine is overheated, and the piston fails, causing the rings to break. Or when an injector fails open in a common rail engine, and torches the piston. Or when a cooling nozzle fails and the piston melts. But all of those scenarios start with a failed piston, then ruin the ring. Yours looks to be the other way around.

 

[Dixon M]

I am not sure of the ethar usage but in my research after finding the issue I have noticed it is quite common for the 03-07 common rail engine to have broken rings, as far as buying a used motor that is how I found this sight in my research the rear geartrain cummins are popular in busses,rv, and my style of truck but i was unsure of buying a motor and the ecm not having the right program for the allison transmission the ones I looked at had a different idle speed than my current combo. And on my call to cummins insight the lady told me my cpl was good for 240hp and I have located a dealer close by to reprogram the ecm for $550 that is my planned route.

 

[EastCoastCB]

I see.
what transmission do you have?
You can probably change the idle etc yourself. Several forum members have bought their own diagnostic connectors and do that kinda stuff.

 

[Dixon M]

I have the Allison 1000HS 5 speed. The cheapest take out was 4500 dollars that put me on a hunt I checked coparts for a vehicle to salvage the motor out of but nothing was close to me and I do not want to deal with the logistics of getting it to me.

 

[EastCoastCB]

I understand.
One other option I almost took when needing to replace an engine was rusty buses from the midwest. OH takes good mechanical care of their buses, so if you find a good runner for less than a couple grand you get a lot of extras and can even recoup some of the money. May even be able to find one with a real nice set of tires.

This ones a takeout that was reman'ed in 2011. 270 hp.
https://www.truckpaper.com/listings/truck-trailer-attachment/for-sale/190471031/2011-cummins-isb-59

 

[Dixon M]

That's a good deal on a 5.9 but I have the CP3 pump mounted on the rear with the power steering pump I need a motor like this one.
https://www.ebay.com/itm/CUMMINS-6B...021007?hash=item2157af354f:g:4tkAAOSwdGFYvO7s

 

[Dixon M]

Cleaning and painting parts waiting on other parts to come in so the machine shop can finish the block and head.

 

[Dixon M]

Working on assy of the motor today got the crank all cleaned up and in the block 4 main caps on and with the heat here in Florida I was trying to keep the sweat out of the motor tore a glove and have to take a break so that my hands dry up enough to put another pair of gloves on LOL

 

[Dixon M]

Ok crank is in have .003 to .004 on clearance and .008 thrust so that is done will move to measuring ring end gap see what I come up with. I am slow at assy.

 

[Dixon M]

Checked all the ring end gaps pulled old pistons off rods cleaned every thing well and hung all six pistons next sunday they should be back in the block. :baconflag:

 

[cadillackid]

thios is the way to go.. used engine just means used issues.. service sleeves and new pistons are the wayu to go.. gives you a chance to make sure the emngine is sludge free, that the other parts are good too, ie oil pump, timing gears, bearings, seals etc..



I would choose this method anyday.. the allison 1000 is a great trans, im running a 6 speed I swapped in behind a IH 7.3 (T444E)..

 

[Dixon M]

Yea I did not want to deal with the hassle of possible getting another problem and I like the idea of knowing what I have I had the block sleeved on number 6 and all holes bored .020 over new pistons, bearings, rings and all new gaskets and injectors it should last another 250,000 miles with easy.
Fun fact looked up the crankshaft weight last night comes in at 130lbs I knew it was heavy.

 

[Dixon M]

Just thought I would ask here looking to borrow a Cummins tool for the rear main seal this motor has unitized seals on the crankshaft seals and I for sure do not want any oil leaks. Cummins tool number 3064660 tried local marine cummins outfit and was able to borrow the tool for the front crank seal but they only have the installation tool for the old style rear main. The dealer in WPB says they don't loan out tools but I am going down there this week to get a new water pump and thermostat and will talk to the techs and see first hand. Just checking all my options before I go oldskool method LOL.

 

[Dixon M]

Well I broke down and bought the tool ready to install the seal and get this job done hopefully before the end of the month