L3940 engine knock / tapping noise

[HUDSKY]

We have a 2010 L3940 HST. 321 hours. Has a tapping noise in engine from 45 seconds after start up till approx. 2 minutes of run time. When Kubota service checked the oil they found aluminum shavings in the oil. It has been in the local Kubota service garage 3 times. (They don't know what's wrong but they can hear the engine noise) Asking for your help on fixing the engine noise ??

 

[North Idaho Wolfman]

Sadly it sounds like your going to need to do an engine rebuild.
It could be serious or it could be simple, but there is almost no way for sure to know without tearing into it and looking for damaged parts.

 

[lsmurphy]

Out of warranty?

Aluminum? Does not sound good, not at all, and I would not run it anymore.

 

[hodge]

Out of warranty?

Aluminum? Does not sound good, not at all, and I would not run it anymore.

That's my question- where would aluminum come into play inside the engine?

 

[lsmurphy]

That's my question- where would aluminum come into play inside the engine?

Piston slap/wear?
Burned completely through the rod bearing and now eating the rod?????


I don't know.....should otherwise be completely iron.......no?

 

[hodge]

Piston slap/wear?
Burned completely through the rod bearing and now eating the rod?????


I don't know.....should otherwise be completely iron.......no?

Are the pistons aluminum? Certainly the rods are iron.

 

[North Idaho Wolfman]

Rod's and pistons are aluminum as is the crank journal end caps and bearing / seal holders.
One thing it could be that would be a real easy and quick fix would be the valve rocker shaft assembly.
I would pull the valve cover first and look there for any problems, that is also aluminum.

 

[kuboman]

An oil analysis will tell you were it is from and what other metals are in the oil. Best find out soon.

 

[HUDSKY]

An oil analysis will tell you were it is from and what other metals are in the oil. Best find out soon.

Yes Kubota dealership in Bellwood, Pa did the service on the tractor, they sent the sample to be oil analysis Results said there was aluminum in the oil, did not say what kind or where from in the engine. Kubota Rep came from Ca. said there was nothing he would do, unless it blew up. Rep said this tractor was the only one making this tapping sound. We are trying to find the problem & fix before it runs out of warranty. The Kubota in Bellwood told us today the engine out of warranty is between 5K & 6K.

"The Kubota Company" its self does not want any dealership to open the engine. You & I both know the only way to see or fix the problem is to open it.
Thank you everyone for your help in fixing our headache.

 

[hodge]

Yes Kubota dealership in Bellwood, Pa did the service on the tractor, they sent the sample to be oil analysis Results said there was aluminum in the oil, did not say what kind or where from in the engine. Kubota Rep came from Ca. said there was nothing he would do, unless it blew up. Rep said this tractor was the only one making this tapping sound. We are trying to find the problem & fix before it runs out of warranty. The Kubota in Bellwood told us today the engine out of warranty is between 5K & 6K.

"The Kubota Company" its self does not want any dealership to open the engine. You & I both know the only way to see or fix the problem is to open it.
Thank you everyone for your help in fixing our headache.

That's discouraging and disturbing. I would have hoped and expected that Kubota would honor the warranty, and determine what is wrong.

 

[aeblank]

Seems to me you need to establish that today is the day the problem started (inside warranty). Document that they won't repair, etc.

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