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I recently had one fuel injector go out on my drill rig whitch is using a CAT 3406 on the deck. I changed all 6 at one time. Immediatley after replacing the injectors the engine started using 1 gallon of oil efter every 12-14 hours of use. After approximatley 50 hours of operation the engine threw a rod through the side of the block. Any ideas??
The engine never heated up or lost oil pressure.
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When you say the injector went out what was it doing? Was it dumping fuel into the cylinder? Was the engine oil contaminated with fuel and if so was it changed? If the injector was "pissing" fuel into the cylinder it may have burned the piston crown.

The bad news is the oil consumption problem should have been looked at as soon as the problem was noticed. If you do a failure analysis on this engine I would pay attention to the cylinder that had the bad injector. Pay attention to the piston, rings and cylinder walls of this cylinder and look to see if the piston shows any damage in the form of a partially melted piston.

The 3406 is a tank of a engine with a great service record. Properly maintained and operated they are a very long lasting engine. I have overhauled many of them in trucks over the years that were pushing well over 1 million miles.

One suggestion would be to start a UOA (used oil analysis) program if you are not doing one now. It is a great way to catch problems before they become a failure.
Here is just a thought on the engine throwing a rod. If when the engine was stopped, fuel drained into the top of the piston and then when the engine was re-started the fuel was trapped in the top of the cylinder and could not be compressed. This would bend and damage the rod and lead to the eventual failure.

Dear Crjerry
I know that engine pretty good especially on drill rigs as DM30. tHAT ENGINE IS RUNNING IN A VERY HIGH LOAD AND HIGH HP.
The bearings are sensatives and a connecting rod that 'ventilate" the block is not a rare case.
You must monitor very carfully the oil. If you notice irregular Cu, you must stop and repair.
sOMETIME THE SOURCE OF the Cu is connecting rod bushing or main bearing. That engine last not more that 10000 hr. The event that you describe could be a problem in the fuel pump that lead to over power.Also, you must protect the rig by installing automatic temp shut down.
I would say the injector was dribbling or somehow leaking fuel into the cylinder. It may have caused liner wash removing the lubrication and causing scoring of rings. An earlier poster suggested a burned piston as well; again caused by un-atomized fuel on the aluminum piston causing overheating and deterioration (shedding, erosion). Eventually, the piston overheats and seizes. I suspect the piston is in many fragments and hard to peice back together.
I suggest at least cut open the lube oil filter and check for debris before running the engine again. Better yet, get a bore scope in the piston or from below and examine the liners before running this unit.
If you know the injector is bad then you know the fuel likely diluted the liner lubrication. This engine does not have any meaningful temp sensors to monitor so you have to play it safe. If you hear a noise don't start it again until you verify the source (if it's mechanical source, don't start until the repair is done). Otherwise you'll be buying at least a new block and probably a crankshaft to say nothing of the downtime.
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