Brand new L2501 started making a nasty noise at 6 hours

[JWR]

Arclight -- can you elaborate a little on the photos ? What are we seeing and what is damage versus what is normal, etc.

Especially, what is that bright circular spot that seems to be in the middle of the uppermost piston ? That is a piston, right? Are all those random markings on both the head and the piston damage from dancing fragments of something scratching them? What is the rod like protrusion above and between the valves? Is the smaller protrusion a glow plug or is it the other way around? Is the alien culprit that caused the damage anywhere to be seen or is it known?


Sure seems that the dealer has turned out to be a keeper after all. It is always better to be on good terms with your dealer if at all possible. You need him as much or more than he needs you in the long run.

Please keep us updated.

 

[ruffdog]

Depending how hard the item is that gets in the cylinder, they can change shape from all the hammering. The only thing I have seen that doesn't change shape are ball bearings. They put very pretty spherical dents into the head and piston. That piece could have been stuck in the intake port since the post foundry cleaning process....who knows? Aluminum pistons will grow their diameter while being hammered and will get tight in the cylinder bore. In the case of the handful of ball bearings, the pistons grew until they cracked the block.

 

[ruffdog]

Arclight -- can you elaborate a little on the photos ? What are we seeing and what is damage versus what is normal, etc.

Especially, what is that bright circular spot that seems to be in the middle of the uppermost piston ? That is a piston, right? Are all those random markings on both the head and the piston damage from dancing fragments of something scratching them? What is the rod like protrusion above and between the valves? Is the smaller protrusion a glow plug or is it the other way around? Is the alien culprit that caused the damage anywhere to be seen or is it known?


Sure seems that the dealer has turned out to be a keeper after all. It is always better to be on good terms with your dealer if at all possible. You need him as much or more than he needs you in the long run.

Please keep us updated.

Being that the marks in the piston/head stay pretty consistent, I would say the item is hard, and was broken into a few parts, and may have started out as a part of a spring?:2cents:

 

[auroraproject]

Arclight -- can you elaborate a little on the photos ? What are we seeing and what is damage versus what is normal, etc.

First picture is the block with the piston at near top dead center. There's a cavity in the top of the piston and that's the mini-chamber that the fuel and air are injected into at the start of combustion. That whole flat space around the cavity should be smooth as glass. However, you can see the little fence-staple sized piece of wire, fragments, and all of the imprints of it on the top of the piston and on the head in the second picture. When the piston is at top dead center, there's almost no clearance between the piston and the head, so this little piece of wire bouncing around up there was getting HAMMERED into the head with every stroke of the piston. You can see how many times it happened in the 60 seconds or so this tractor was run after the issue started.

 

[auroraproject]

Being that the marks in the piston/head stay pretty consistent, I would say the item is hard, and was broken into a few parts, and may have started out as a part of a spring?:2cents:

It looks like a box-staple or something. That would be made out of a relatively mild steel, and would explain the lack of marks on the valves and tons of them on the piston. Maybe it's from when the engine was assembled, or when the engine was installed in the tractor. I wonder how the parts are packed when being sent to the manufacturing facility.

 

[atsah]

It makes you you wonder if there is disgruntled employee somewhere..

 

[ruffdog]

It looks like a box-staple or something. That would be made out of a relatively mild steel, and would explain the lack of marks on the valves and tons of them on the piston. Maybe it's from when the engine was assembled, or when the engine was installed in the tractor. I wonder how the parts are packed when being sent to the manufacturing facility.

Hehe......I could hear it now...."I was wondering where that packing staple flew when I unpacked a box that holds engine parts..."

 

[auroraproject]

What is the rod like protrusion above and between the valves? Is the smaller protrusion a glow plug or is it the other way around? Is the alien culprit that caused the damage anywhere to be seen or is it known?

There's the costly little bugger.


I'd guess the larger protrusion is the glow and the more recessed one is the fuel injector, but I don't know for certain

 

[sd455dan]

Sure does look like some kind of staple or wire.
Pics Really show just how little clearance there is between the piston and cylinder head at TDC on many diesels

Great that Kubota sent a new factory engine and the dealer has a proficient mechanic to get you back to tractoring ASAP.

I bet the factory guys are looking at this engines build history - parts supply,inspection and build process to find any place that a staple or wire has a possibility of being introduced into their engines.
An ISO 9001 certified manufacturer like Kubota will take steps to make sure this does not happen again.

 

[auroraproject]

I bet the factory guys are looking at this engines build history - parts supply,inspection and build process to find any place that a staple or wire has a possibility of being introduced into their engines.
An ISO 9001 certified manufacturer like Kubota will take steps to make sure this does not happen again.

Stuff like this is **** for process improvement folks. At least it is to me