Why Did It Break

wdlanning

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L3750, L4310, B20, Genie Boom
Nov 7, 2016
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philadelphia pa
I have an D1803 engine from a L3400 with a big hole in cylinder wall #3. The connecting rod is bent and the piston is really destroyed. Two push rods are also bent. No visible damage to the head. The crank does not appear damaged at all. The other two cylinders appear normal. The oil does not appear to have water. Head gasket appears intact. I am in process of taking the engine apart.
Without knowing the cause for the bent rod, I am concerned that I may not fix the root cause of the problem. I will have the crank tested and will replace the one rod and all pistons and bearings. What else should I test to determine the cause for the bent rod? If water got into the engine, wouldn't it be evident in all cylinders? Can a bad injector be the culprit?

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Kubota Newbie

Active member

Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Dec 28, 2010
533
81
28
Mount Vernon, Ohio
When did it happen???
At Start-up?
If so, and no ether was used then it's likely a water issue. Does not take a very big leak. International Navistar had an issue with head gaskets years ago. If the water happened to leak into a cyl that was at bottom of intake getting ready to move up on the compression stroke and one of the other cyl's fired at start-up, bang, exactly the outcome you experienced. Of course the problem often went unnoticed for a while because the leak could occur during shut down for a cyl on the power or exhaust stroke and the water would then often just be expelled from the motor without harm.
 

Kubota Newbie

Active member

Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Dec 28, 2010
533
81
28
Mount Vernon, Ohio
Worth noting that the water can come from more than one place. Assuming that it didn't come in through the intake 'cause something was left undone or uncovered the usual culprits are: Head Gasket, Crack in Cyl Head that extends into the water jacket. The latter is not always obvious when the head is cold but can open up when it is hot. This motor making any white smoke before it went bang?