Are CR's prone to breaking rings

So did they fix this with 6.7L's because I don't hear about it as much, unless that's just because they are less people getting crazy with them so far?
 
My 05 had broke rings on 1 and 6. It wore a ring grove in that .020 took it out.

200K, stock everything other than a Bullydog and the last 6 months were with 100hp II injectors. I suspect the tight ring gap and hot cyl temps from a tuner, stock air and a heavy foot.
 
Also subd, so 03 eary 04 motors are the good one to have? I thought they had a bunch of injector problems and burned up pistons? Or was that the 04.5 and up? I think I'll keep the dinosaur a few more years......
 
TheSilverBullet said:
Also subd, so 03 eary 04 motors are the good one to have? I thought they had a bunch of injector problems and burned up pistons? Or was that the 04.5 and up? I think I'll keep the dinosaur a few more years......
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Look up re-enterant vs non re-enterant piston bowls and you will have alot of your answer.
My impression on the rings is that the issue isn't isolated to CR engines and didn't stop until the last 5.9 revision (06-07 for chrysler)
This is my opinion of course.

And spelling bee champions need not rape on my attempt on the above butchered terminology.

Squeaky Wheel
 
I'll keep my stock '03 with 335k miles on it. I use to haul heavy as hell with it and never had a minutes trouble at all....even with a programmer. Maintenance was done once a week though....oil, filter, and fuel filter change.....averaged 3500 miles a week.

I attribute that to the longevity of my engine. Nowadays its a DD with Flux II's but the maintenance stays on schedule and I'm hoping to get at least another 3-400k miles out of the stock engine. I can't stress enough how important maintenance is!!!!!!!!!!!!!
 
TX_5.9 said:
I'll keep my stock '03 with 335k miles on it. I use to haul heavy as hell with it and never had a minutes trouble at all....even with a programmer. Maintenance was done once a week though....oil, filter, and fuel filter change.....averaged 3500 miles a week.

I attribute that to the longevity of my engine. Nowadays its a DD with Flux II's but the maintenance stays on schedule and I'm hoping to get at least another 3-400k miles out of the stock engine. I can't stress enough how important maintenance is!!!!!!!!!!!!!
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How do you know you don't have broke rings?
The engine that I had with the broke rings was bone stock. I bet you have broke rings and don't even know it
 
DISTURBED said:
How do you know you don't have broke rings?
The engine that I had with the broke rings was bone stock. I bet you have broke rings and don't even know it
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I sure hope you're wrong. now you've got me paranoid about it. dang it!!!
 
Snedge said:
At 335,000 miles, you could choose a handfull of things to be paranoid about. $.02
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come on now......that's just wrong!! this ol girl been great to me. like I said, I'm super meticulous about maintenance and I know things happen but I feel that most things failurewise happen because of neglect.
 
TX_5.9 said:
come on now......that's just wrong!! this ol girl been great to me. like I said, I'm super meticulous about maintenance and I know things happen but I feel that most things failurewise happen because of neglect.
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ha ha I'd agree with you on the neglect part. I don't think breaking the rings comes down to neglect though.
Can you find relative compression in CR's through the ECU reading?
 
I will step up and say that I have pulled a LOT of 6.7s apart.

I have only seen 2 with broken rings and I feel it was secondary to other damage, like a dropped valve that tore the hell of the bore and/or piston.
Overheating is what got one other one and I still think the ring only broke because it was run with the bore roughed up, or it broke when it was ran hotter than hell.

IMO, a lot of the issue with bad rings went away with the 6.7 and the very BEST thing about the 6.7 is that the injector design is worlds better.
The WORST part of a 6.7 (as well as a 5.9) is the confounded fracture cap rods.

FWIW, USUALLY broken compression rings (or scored cylinders) show up as some sort of blow by, weather mild, or blowing the cap off the valve cover and fogging out the draft tube, broken rings will show up.

A leak down test will spot them post haste.
A simple cranking variance test will tell a lot, too.

A LIGHTLY leaking cylinder can show up while cranking without firing it, once it has been run.
Just look at the oil fill hole on a warm engine, while cranking it with the fuel disabled.

New engines (under 70-80k miles) and engines with little hard usage (helps seat rings) can, and oftentimes do, haze just a bit from the crank case until the rings fully seat, which is why you should MAKE A NEW CUMMINS WORK.

Mark.
 
great post nixon. couldn't agree more.


DISTURBED said:
So to my original reasoning for asking. How is this fixed? Can you tune this issue with the cylinder temps out to make it live longer?
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for those of us that have the post injection even disabled, doesn't this help? of course controlling timing does...
 
Mark Nixon said:
I will step up and say that I have pulled a LOT of 6.7s apart.

I have only seen 2 with broken rings and I feel it was secondary to other damage, like a dropped valve that tore the hell of the bore and/or piston.
Overheating is what got one other one and I still think the ring only broke because it was run with the bore roughed up, or it broke when it was ran hotter than hell.

IMO, a lot of the issue with bad rings went away with the 6.7 and the very BEST thing about the 6.7 is that the injector design is worlds better.
The WORST part of a 6.7 (as well as a 5.9) is the confounded fracture cap rods.

FWIW, USUALLY broken compression rings (or scored cylinders) show up as some sort of blow by, weather mild, or blowing the cap off the valve cover and fogging out the draft tube, broken rings will show up.

A leak down test will spot them post haste.
A simple cranking variance test will tell a lot, too.

A LIGHTLY leaking cylinder can show up while cranking without firing it, once it has been run.
Just look at the oil fill hole on a warm engine, while cranking it with the fuel disabled.

New engines (under 70-80k miles) and engines with little hard usage (helps seat rings) can, and oftentimes do, haze just a bit from the crank case until the rings fully seat, which is why you should MAKE A NEW CUMMINS WORK.

Mark.
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Awesome! Thanks for the info. I think I might pick up a 2nd truck and I can't decide if I want to deal with piston rings or a 68rfe ;-) I do like the idea of more displacement though. Oh well, still in the research phase.
 
Is this something I should be worried about? My truck burns hardly any oil, has no blow by and runs strong. Its an 03 nv5600 with 170k on her. But I just bought a twin kit for 5k, injectors for 3k, DD clutch and hydraulics for 1.5k and a cp3 for 2k. Other stuff too like valve springs and a fass... So, did I just spend too much money on something that could have broken rings and could fail on me? I had never heard of this issue till I read this thread. Thanks guys.
 
BadBowtie03 said:
Is this something I should be worried about? My truck burns hardly any oil, has no blow by and runs strong. Its an 03 nv5600 with 170k on her. But I just bought a twin kit for 5k, injectors for 3k, DD clutch and hydraulics for 1.5k and a cp3 for 2k. Other stuff too like valve springs and a fass... So, did I just spend too much money on something that could have broken rings and could fail on me? I had never heard of this issue till I read this thread. Thanks guys.
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makes you feel all tingly on the inside don't it?? :)
 
BadBowtie03 said:
Is this something I should be worried about? My truck burns hardly any oil, has no blow by and runs strong. Its an 03 nv5600 with 170k on her. But I just bought a twin kit for 5k, injectors for 3k, DD clutch and hydraulics for 1.5k and a cp3 for 2k. Other stuff too like valve springs and a fass... So, did I just spend too much money on something that could have broken rings and could fail on me? I had never heard of this issue till I read this thread. Thanks guys.
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I bet with a small enough borescope, you could pull injectors and take a peak inside, but the way I understand it is that it's just a matter of time.
 
Very nice info here anyone feel free to post more pics on this as well as mileage, again good thread.
 
Well I read a ton last night about this issue. Most stories I read were of the later common rails. In fact I didn't read any about the 03-04s... But I'm not saying it couldn't happen. I read the 03s had different pistons and a different placement of the top ring... That it was further down the list on and not as close to combustion? Also I read they had better oil squirters? Anyways... I just hope I got a good one and it doesn't happen to me.
 
BadBowtie03 said:
Well I read a ton last night about this issue. Most stories I read were of the later common rails. In fact I didn't read any about the 03-04s... But I'm not saying it couldn't happen. I read the 03s had different pistons and a different placement of the top ring... That it was further down the list on and not as close to combustion? Also I read they had better oil squirters? Anyways... I just hope I got a good one and it doesn't happen to me.
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The early CR engines are certainly LESS likely to break rings, but I don't think ring placement is as much the culprit as the added injection event (which creates more heat) on the '04-1/2 and up engines.
Certainly the bowl design may also play a role.
I feel lower ring placement would certainly HELP, but the material the ring is constructed from is as much to fault as the placement of it.

As far as piston oilers, the '03 and '04 engine did get all-metal oilers, instead of the plastic ones.

FWIW, the first few (hundred? thousand?) 2003 production 5.9 engines also got MACHINED CAP rods instead of the troublesome (IMO) fractured cap ones, though they are very, very rare to find in a CR.
I have had 3 of those engines and I may have a 4th sitting here that I need to tear down, yet.

Also, there is yet one more problem that people may or may not be aware of, and it is primarily an EARLY COMMON RAIL failing.
The earlier cylinder heads are built with a thinner CAST IRON valve seat.
These seats have a propensity of working loose and making a mess of things.
While ANY cast (or even hard steel) seat CAN work loose, given enough heat and abuse, it's a particular problem on early CRs and even some VP-44 engines.

Most everything that goes wrong here in this thread is generally the result of excessive heat in the cylinder, which means that if these engines didn't get overheated, or have more fuel pushed through them (creating more heat), they'd likely not have "as much" of an issue.
Certainly there would be less failures.

While heat is the enemy, heat is also necessary.

Mark.
 
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