Meltdown and rebirth of a 6.7 Cummins

anderson750

I'm working on it Rose
Location
Price, Utah
My 2011 Ram 3500 dually has been a great truck. Much of what I did to it initially was based around what L.T. did with his Project Built for towing. I bought this truck in November of 2011 with 29K miles on it and I completed the delete before the truck had 40K on it. Many people are scared to do this due to losing your warranty, but in all honesty if you research any history on problems with the modern diesels, whether it be Ford, Chevy or Dodge, all the problems are usually found within the emissions system. My list of modifications are as follows:
  • DPF/Cat delete
  • EGR Delete
  • H&S tuner with custom tow and transmission tunes from Anarchy diesel
  • Water/methanol injection (I have a thread on here somewhere about the install but cannot locate it)
  • 5" turbo back exhaust
  • upgraded intercooler
  • cold air intake

I have used this truck mainly for towing a 45 foot Cyclone toy hauler to motorcycle races throughout the west. Dry, this trailer has a claimed weight of 14,500 lbs. When fully loaded with water, bikes, gear and everything else I am somwhere between 17,000 to 18,000 pounds. I have never been short on power to pull my trailer up any grade, but EGT's have always been a battle. I will be up front and honest that I have not been a little hard on this truck, but it has always been reliable.

Well after almost 5 years of hard use, I caused some major damage between Fillmore and Beaver......aka the Filllmorebeaver area on my way to a race in Caliente, Nevada. The last couple of trips, the truck seemed a little down on power but the truck was definitely working harder on this trip. We had a head wind the entire way and it just struggled do maintain pull on even some of the smallest grades. Just about the time I was going to make that climb after Fillmore my coolant quickly spiked to 247 and I backed out of it. The temp came down quickly and when I stepped back on the gas I heard the dreaded knock. I was able to limp it to Beaver and thank God for good friends, because I had one traveling a few minutes behind me that got somebody to bring me his spare truck so we could get to the race.

While waiting in Beaver I went the spectrum of what it could be, since I did not yet know what had happened. I knew the knock was coming from high in the motor and was not a bottom knock, so I was hopeful that it may have just been an injector. This video does not show the sound very well, but you can hear the knock.


Here is one for the Chevy guys. Duramax recovering a Cummins. Technically there is towing happening, so it is ok that the tow mirrors are out.


I got the truck home and my friend who has done all the major work on this truck started the diagnosis. We ran a diagnostic where we killed each injector individually. When we killed the #6 injector, the sound pretty much disappeared...........pretty much........not entirely. Hopeful that it may only be an injector he set about swapping the #1 & #6 injecors.


Well, this is where our luck ran out since the knock did not follow the injector and I now feel my wallet starting to get so light it will float like it is in zero gravity. Since it is the #6 cylinder making all the noise, there really is no other choice than to pull the motor to get the diagnosis done.


With the head pulled, there was nothing that immediately jumped out other than the #6 piston and valve area had more carbon build up than any of the other cylinders.




Being that the knock was up high and it was not the injector, we were pretty confident that it was the wrist pin. So, out comes the piston and this is what we find.



 

anderson750

I'm working on it Rose
Location
Price, Utah
What exactly has contributed to this, I am not 100% sure, but I believe it has to do with failing injectors. The truck now has just shy of 118,000 miles on it and when we had the injectors tested, 4 of the 6 failed the pop test. What to do now? Well, a new truck is gong to be in the 60-70k range, and I love this truck with everything deleted, so I am going to rebuild this motor and make it better for the job. The truck has plenty of power....my biggest problem is EGT's. After some research and consulting with a few people, here are my build plans.

  • Have the block machined .020 over
  • Mahle coated pistons
  • ARP 625 head studs
  • Rebuilt stock injectors
  • Add a turbo compound kit from Industrial Injection


I am open to peoples thoughts and opinions on this but understand that my ultimate goal is not to build a race truck but build a motor that will do the job of getting us to races. I do not need more power than the 6.7 delivers in it's deleted form, I just want to drop the EGT's under load. The Mahle coated pistons will tolerate heat better. My reasoning for just going with stock injectors is fully because a bigger injector will only start to introduce more heat with the extra fuel. I probably could get away with the lower tensile ARP head studs, but in the whole scheme of things, what is another $600 for the best head studs.

Here is one for you Ford guys. A Cummins motor being hauled by a Ford.



Right now the block is away to get machined.
 
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Greg

Are you not entertained?!
Admin
Thanks for documenting & sharing this! Sucks it happened, but looking forward to the changes! I'm impressed with all the work you've done on your own. :cool:
 

I Lean

Mbryson's hairdresser
Supporting Vendor
Location
Utah
Watching. I don't even have a Cummins, but this interests me anyway. :)
 

anderson750

I'm working on it Rose
Location
Price, Utah
Looking forward to your write up... I have the same year and nearly identical mods (I don't have meth, but have got CNG)
How many miles ya at? 68RFE?
I am just shy of 118k miles. When I did the delete, I bought the custom transmission tune form H&S that brings the line pressures up. I think this is key to getting these transmissions to survive for any amount of time if you are towing heavy loads. I have not babied this thing and it still is working great. Last year I bought a custom tune from Anarchy Diesel that changes my tow tune and gives me torque converter lock out in 2nd gear. With that early lock out, it pulls from a dead stop much easier and if I am going down a dirt road slow, my transmission does not get heated up since it is locked.

I know it is not a matter of if but when I will have to go into the transmission on this thing, but I have gotten a lot more mileage with no problems than others that I have read. I know it is not because I have babied it. I will have to be a little more careful with the compound set up.

What are your thoughts on the CNG? What kit did you use?
 
I'm at 99,574 miles... My over drive clutches started acting up around 98k... If I have the H&S on stock and no CNG it's fine, with CNG or even the tow setting (carrying my camper or towing) I get a fault when I down shift from 6th... If I manually downshift before getting in to it's fine.. Trying to put off the rebuild/upgrade as long as I can cause its big $$$.

I used the regulator from Utah CNG and sourced some Ford tanks (twin 4gal equivalent) that I mounted where the spare goes... I really like it, it's quite a power adder and is typically under 1.70/gal.
I was hoping for lower EGT's and a little better mileage with it... But it raises the EGT's actually (about as much as the tow tune) and my diesel fueling doesn't cut back as much I would have expected... I've got the reg cranked up pretty high, and I'll use the 8gal CNG at about 15-17gal diesel use... I'd like to get it closer to 50/50 eventually.
For the price (I'm in to it about $480 total) I'm very happy with it.
 

anderson750

I'm working on it Rose
Location
Price, Utah
Is the code your getting a low line pressure code? I have been getting a code for that for a long time. It only shows up when I am towing and I can tell it is there when my transmission downshifts from 5th to 4th because it is not a smooth shift.....rather harsh actually. I never get any clutch slipping and it is fine once I have cleared the DTC.

Are you running the H&S transmission tune that brings the line pressure up?
 

sawtooth4x4

Totally Awesome
What are you using to keep track of the EGT's?

What were you running for EGT's before the piston burned up?

Thanks.

I'd like to monitor the stuff on my new truck. I don't tow anything that heavy, but with all the emissions crap on my truck I'm curious how close I am to burning it up. That F350 I was towing on the trailer probably put me around 14-15K lbs. It pulled it up out of helper without even breaking a sweat. I just had to slow down for corners. it did 60-70 mph with ease. I got about 15 mph towing it back home. I'm really impressed with it so far.
 

anderson750

I'm working on it Rose
Location
Price, Utah
The display for the H&S has an EGT readout. The probe is placed above the #6 exhaust in my EGR block off plate. I also have a readout on my water/methanol controller. This probe is placed in the collector just above the turbo. Interesting fact about this is that the probe above the collector will read about 200 degrees hotter than the other under heavy load and about 100 degrees hotter under normal towing load.
 
Is the code your getting a low line pressure code? I have been getting a code for that for a long time. It only shows up when I am towing and I can tell it is there when my transmission downshifts from 5th to 4th because it is not a smooth shift.....rather harsh actually. I never get any clutch slipping and it is fine once I have cleared the DTC.

Are you running the H&S transmission tune that brings the line pressure up?
Yeah I've got the H&S trans tune. (I actually turned it up to the next setting, which is 225 I believe... Although the stock pump can only push about 180, seemed to help when I turned it up from the 170 it was at)

Started out with P0868 (low line pressure) and P0871 (pressure sensor/switch) I suspected electrical or sensor because of these 2 faults, but read online it could be filters... And I happened to have put aftermarket filters in about 15k ago. (These faults put me in limp mode) - happened twice, both while downshifting with a load. Also had the truck die twice right after cold start when coming to a stop (torque converter didn't unlock) So I dropped the pan and put in Mopar filters. (Turned up line pressure at that time)
Seemed a fix for a while, then threw P0868 again along with P0729 (gear 6 incorrect ratio) This has happened a couple times now, no limp mode though, just a MIL light. Only when I have a power adder (H&S above stock or CNG on - loaded or unloaded) Leads me to believe my over drive clutches are the unhappy culprit...
 

anderson750

I'm working on it Rose
Location
Price, Utah
There was a recall on one of the shift solonoids. I had it throw me into limp mode one time. My dealer did not care that it was deleted when I took it in.

I love the 2nd gear lockout that I have with the tune from Anarchy. Great for taking off and having the engine brake for one more gear when in traffic.
 
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There was a recall on one of the shift solonoids. I had it throw me into limp mode one time. My dealer did not care that it was deleted when I took it in.

I love the 2nd gear lockout that I have with the tune from Anarchy. Great for taking off and having the engine brake for one more gear when in traffic.
I'll have to check in to that recall...

Been on the fence for a while if I wanna buy MCC and a custom tune or just go straight to EFILive instead... Your tune from Anarchy $225?
 

anderson750

I'm working on it Rose
Location
Price, Utah
who is doing the machine work for you?
Sorry Rick, I missed this question earlier. I am having Industrial Injection do the machine work and I am buying most the parts from them. Their pricing was much better than one of the other major diesel shops up there......plus one of the owners is originally from my neck of the woods.
 
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