Bad piston, ya' think?

[Mark Nixon]

View pics, then commentary below:



This was taken out of a 1997 Cummins from a 1 ton with an automatic.
The turbo was totally garbage, it did the "teeter-totter" thing when I checked it for play, it was horrible.
The seller told me he drained AT LEAST a gallon of oil from the intercooler.

My confusion is with the damage done to the piston.
Could the meltdown have been the result of the turbo pushing oil, or did an injector possibly lock up and drown the cylinder to melt down the piston so severely?
You can't see it directly, but the piston not only is melted down the side, but it's cracked from the top of the piston to the bottom of the skirt, as well.

Interestingly, the crank isn't even close to what one would expect from an engine that (appears to) have ran out of oil.
Sure, the crank was TIGHT (still turned, the engine WANTED to run!), but upon dis-assembly it wasn't even close to being scrap metal, likely a .010-.010 grind would clean it up easily.
It seemed more bound up by aluminum metal flakes from the piston, rather than actual main bearing damage.

Another interesting note is that the block is an extremely early '53' STORM block, which could be bored, except that it's likely to crack later.
The truck was built in Mid-July of 1997.

Glad it was cheap and had a P-7100 I can use or off.

Mark.

[Cnp22]

My guess would be injector stuck open. Iv replace two motors for friends and that was the cause.

[Mark Nixon]

My guess would be injector stuck open. Iv replace two motors for friends and that was the cause.

I had a scenario in mind that goes something like this:
High miles (399,000 +) engine, turbo is worn to the point of loosing the bushings.
This causes oil leakage and fin damage, eventually sending debris into the intercooler and intake.
This in turn gets into the cylinder causing damage and the injector tip takes a hit, locking the pintle open, which exacerbates the problem, by overfueling the cylinder.

This all is happening while the engine is losing oil and possibly in a runaway situation, due to the oil entering the intake.

Mark.

[92strokersmoker]

So how do you make sure you injectors dont stick open! Dang thats a gruesom sight! Whats a good thing to pay attention to (noise wise) to grab a sticky injector before this happens?

[ciamcoop]

In an engine that's in good condition a worn or sticky injector will cause a pretty good amount of blue haze at idle. If the injector is really bad you might hear a distinct knock or rattle, it'll also idle noticeably rougher.

[92strokersmoker]

this kinda sucks! Mine I noticed a worse blue idle haze today (more noticeable without the stack) and have noticed some kind of rattle that I thought was a bad valve so I JUST did the valves and it didnt solve it. This got me scared now! these injectors I just put in november. Do I call the place up and get new ones or have em tested first before I jump to conclusions. All I know is I reallllly dont want to pull a head and see the results posted above! Any tests I can do myself?

[ahale2772]

you should notice a sound in normal driving with a stuck injector, sometimes it can sound like a rist pin knock/ a loud ping, usually not soemthing that you can miss unless you listening to Led zeplin and half asleep.

Ive got a buddie that pulled his 96 apart with a similar looking piston, the motor still ran, cranks only needed a polish and cylinders cleaned up at 10over..... very lucky

92stroker, best bet is to do the old cyliner drop test at idle, have the motor running and crack each injector (one at a time) and see if the noise goes away at one point (you will loose a cylinder at the same time but you should notice a difference between a normal cyl and the one with the dead injector)

[Mark Nixon]

92stroker, best bet is to do the old cyliner drop test at idle, have the motor running and crack each injector (one at a time) and see if the noise goes away at one point (you will loose a cylinder at the same time but you should notice a difference between a normal cyl and the one with the dead injector)

LOL, this is kinda' like doing the same thing by removing spark plug wires on a gasser, only you're trading getting zapped for getting fuel spray in your eyes.
Wear goggles and/or stand back while doing this.

Mark.

[ahale2772]

yeah you are going to get sprayed, cover them with a rag...but keep said diesel soaked rag away from the manifold