CM 871 Fuel in the oil

[qmp312]

Ok guys need your help. CM871 demandated @m*m^2. 60k on my inframe bought the best of every thing, the only thing not new is crank, rods & fuel system (all working as supposed to didn't see the need to replace) driving along and doing my thing and oil temp starts to climb above the 235 Mark and fan isn't cooling it down, so I start making my way to the shoulder and oil psi starts to fall and knocking starts in the bottom end. I get to the shoulder & shut down. Yea I'm heavy & pulling a hill. Engine will not turn over (locked up) get it home pull the pan & oil pump. # 1 & # 4 bearing in pieces in the pan oil pump is super hard to turn. Also drained almost 15 gallons of oil. Did 2 different oil samples both came back 19.4 % fuel. That accounts for the extra oil in the pan. What can cause such a failure. I had no indication of anything failing. No drop in mpg, no drop in power, no smoke no nothing just pile of $ gone
:waaaht:

[tree98]

Your oil pressure definitely dropped, you just didn't pay attention. As far as what caused your fuel dilution, could be a lot of things, bad injectors, cracked head, etc. And now that its blown up its going to be a lot harder to figure out what was causing it.

[Waterloo]

Did you do the in frame yourself or did a shop do it? When we tore my motor apart in Rawze's driveway, besides finding all of the wrong internal parts installed... CM2350 450hp in frame kit, injectors and cams installed in my 600hp CM-871...

We also found parts that were about to fail, like the scissor gear on the injector cam, that was ready to blow apart. Also the injector cam plate, a one time use item that installs on the end of the injector cam was also reused, they can fail and come apart. Lonestar10 had the same plate reused on his fresh in frame to... He is in Rawze's driveway right now.

We also suspected the motor was dry started, as the lower end bearings looked like they had two million miles on them, not the 70,000 miles they actually had. And when I was under there undoing the caps for the bearings, they sure did not feel like they had the proper torque on them, they came out pretty easy.

Wrist pins too, quite a few reports of those failing or installed improperly.

Another thing, when installing the pistons, were the rings stepped, the gaps in the rings, some shops have been know not to stagger those gaps, and all of the fuel goes into your oil.

And the liners, mine were not cut, the ledge in the block, even though they assured me the work was completed, it was not. Liners were just bouncing around in there, lucky the block was not damaged. .

And the head, did they install a new head, a new reman head, or even cleaned up your old head and reused? Check the part number on that head. That is getting to be pretty common too, installing the old head or a crap reman and they bill you for a new one.

Just a few things to look at...

[Rawze]

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Fuel in oil problems can be difficult to find. Could be one or more of...

* Gear pump that has gotten leaky.
* An out of date injector on cummin's recall list.
* A crack in the head between the injector and the valve seats.
* Improperly installed or sheered o-ring on an injector.

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With that much fuel in the oil like you described and while the IFSM and all injectors still attached to the head, the head could have possibly been troubleshooted using the adapter plate that is normally used as part of the injector leak-down kit + shop air (+ u.v. die perhaps too) to see if it is loosing pressure, or seeping somewhere.

[qmp312]

Thanks for the replys gonna pressure test the head & go from there.