L3130 engine knock/tick

[sawdustmaker]

I bought a 3130 recently and shortly after I started using it I started noticing a knock that seemed to get worse as the tractor warmed up. I Figured it was a rod bearing and pulled the oil pan and the rod caps and everything looked ok. I then pulled the engine out and put new pistons, wrist pins and bearings in it. I expected to find a spun main bearing. I did find some wear but nothing really bad.
I put it back together and fired it up and within a few minutes the noise came back. I did not pull the cam, but the lobes looked good and the tappets did as well. I'm fairly confused. I've never worked on a Kubota before and its obvious I'm missing something. Could the injection pump, the timing gears, injectors or oil pump cause a knock that's sometimes more of a tick?

 

[North Idaho Wolfman]

I bought a 3130 recently and shortly after I started using it I started noticing a knock that seemed to get worse as the tractor warmed up. I Figured it was a rod bearing and pulled the oil pan and the rod caps and everything looked ok. I then pulled the engine out and put new pistons, wrist pins and bearings in it. I expected to find a spun main bearing. I did find some wear but nothing really bad.
I put it back together and fired it up and within a few minutes the noise came back. I did not pull the cam, but the lobes looked good and the tappets did as well. I'm fairly confused. I've never worked on a Kubota before and its obvious I'm missing something. Could the injection pump, the timing gears, injectors or oil pump cause a knock that's sometimes more of a tick?

Asking us to evaluate a noise via text is just about impossible.
Make a video/audio of it doing it and post the video on youtube and give us a link to see/hear it.

 

[sawdustmaker]

This is before I put bearings in it. I will get a current video soon.

3130

youtube.com

 

[North Idaho Wolfman]

Did you put the thrust bearings in it?

 

[sawdustmaker]

Did you put the thrust bearings in it?

Yes I did

 

[North Idaho Wolfman]

It's super tinny like something in the muffler, like a broken baffle.
or possibly something with the clutch?

Does the sound change when you push in the clutch?

 

[North Idaho Wolfman]

I just remembered another that the shield on the propeller shaft was making that noise.

Another option is alternator or water pump, pull the belt and run it and see if the noise is still there.

 

[sawdustmaker]

I'm sure its in the engine. I'm uploading a video now from tonight.
Depressing the Clutch makes no difference. Also removing belt makes no difference.
It doesn't seem like something in the muffler. I put my hand on the muffler and it does not feel like its in there.

 

[sawdustmaker]

 

[sawdustmaker]

I loosened each injector line and none of them seemed to change the noise.

It sounds very much like a rod knock to me. It is very loud to the point it hurts my ears a little.

 

[North Idaho Wolfman]

ok those two videos sound nothing alike!

Yep you have serious issues, sounds like the pistons are slamming into the head!

 

[Runs With Scissors]

I agree with NIW, that sounds serious.

One trick I use to isolate noises, is to grab a long screwdriver or pry-bar and put the handle against my ear.

Then "carefully" touch the tip to different areas. You will be able to pick out what is making the sound pretty easy.

It's the same concept as a Dr's stethoscope.

(I used to have an actual automotive stethoscope, but it got smashed; thats when I learned about the "screwdriver trick")

 

[sawdustmaker]

Ok. I can pull the oil pan and the head and see what I find. might be a few days.

 

[sawdustmaker]

Yep you have serious issues, sounds like the pistons are slamming into the head!

One of the pistons was scored badly on the sides above the wrist pin. Maybe it is hitting the head. I did not see anything else that could indicate that. I did not look specifically for signs of piston to head contact.

I did not feel any interference when I turned it over by hand.

 

[North Idaho Wolfman]

One of the pistons was scored badly on the sides above the wrist pin. Maybe it is hitting the head. I did not see anything else that could indicate that. I did not look specifically for signs of piston to head contact.

I did not feel any interference when I turned it over by hand.

Have my taken off the injection pump and reinstalled it?
More Importantly have you reinstalled all the shims under the pump, without sealer?
You can do a fuse test with the head on and check clearances.

Fuse test is using a piece of solder in either the injector or glow plug hole and squashing it then measuring it.

Did you use a OEM head gasket?

 

[sawdustmaker]

Have my taken off the injection pump and reinstalled it?
More Importantly have you reinstalled all the shims under the pump, without sealer?

I did not remove the injection pump from the block.

 

[North Idaho Wolfman]

I did not remove the injection pump from the block.

Did you remove any gears under the front gear case cover?
Have you checked the valve clearances?

 

[sawdustmaker]

Yes I did remove the crank. I lined the dots on the idler gear with the corresponding gears. 1 dot for the crank, 2 dots for the injection pump, 3 dots for the cam gear. I had marked it with paint marker but it was smeared when I went to put it back together.
I have not checked valve clearances.

 

[North Idaho Wolfman]

Yes I did remove the crank. I lined the dots on the idler gear with the corresponding gears. 1 dot for the crank, 2 dots for the injection pump, 3 dots for the cam gear. I had marked it with paint marker but it was smeared when I went to put it back together.
I have not checked valve clearances.

Just to clarify, you lined up all the dots at the same time right?

Pull the valve cover and check the valves.

 

[sawdustmaker]

Just to clarify, you lined up all the dots at the same time right?

Pull the valve cover and check the valves.

Yes all at the same time.

I blanked for a second and thought you were asking about of valve to piston clearance

I did not have feeler gauges with me yesterday but checked valve clearance by hand and they all felt normal. ~0.010-0.015"
I will check them with feelers gauges as soon as I can.