Kubota MX4800 lost all coolant

[gbward3]

I was bush hogging and thought I smelled coolant, looked at the gauge and it was in the middle of the dial, steered out of the high grass to take a look and before I stopped the engine died. When it died I looked at the gauge again, still in the middle. I found steam slowly coming from a small hose to the oil cooler, the hose had a hole and all the coolant was gone. I removed the oil dipstick and it was not smoking and did not smell burned or seem extremely thin. When the engine died it stopped like you turned off the key, didn't bog down, stutter, strain, etc. I waited for the engine to cool, replaced the hose, filled it with coolant and started the engine. It fired right up and I drove it up to the barn. When I got off and took off my ear protection I heard a tapping. I have posted a video here:

The engine still has full power, temp gauge stays in the middle, no smoke from the exhaust. After researching here and other places I thought it was a lifter/tappet noise. I pulled the valve cover and checked all valve clearance, they were all within spec. I am assuming that means that there is not a bent rod or stuck lifter?? I noticed on here that when talk of a tappet noise comes up there is a discussion of oil so since it was time for an oil change I thought I would put it back together and change the oil. Rotella 10w-30 as called for in the manual. Fired it up and the tapping is still there.

When I changed the oil, I did not find any glitter in the oil, cut open the oil filter... no glitter. I got a mechanic stethoscope and it sounds like the noise is coming from the 3rd cylinder. I can hear it from the bottom of the crankcase to the head, about the same intensity. You can hear it all over but definetly louder from the 3rd cylinder. Tapping doesn't sound terrible but it's new.

Engine is a Kubota V2409-cr, tractor has 330 hours on it.

The next thing I'm thinking is maybe a piston rod bearing?? Any thoughts would be appreciated. Thank you in advance.

 

[Cycledude]

Only 330 hours hopefully it’s still under warranty

 

[Gordon Gould]

Have you come to any conclusions as to what happened ?

gg

 

[dodge man]

It doesn’t sound good to me, like there is some kind of damage. I’m not sure how the temp gauge works on your tractor but on a car I had with no coolant the temp gauge didn’t work because there was no coolant to reach the sensor and make it go up or down.

 

[hube2]

I just listened to your video. To me it sounds like rod knock.

 

[stevem5215]

The fact that it quit is probably bad news. And now a tapping noise makes it worse. I'd guess rod or crank noise personally.

 

[5030]

I just listened to your video. To me it sounds like rod knock.

+1. Hopefully you have a warranty because it's come apart time.

Problem with temp gauges (all of them) is, if there is no coolant in contact with the sensor, it won't read hot.

That is a solid rod knock, probably big end and the crank has damage as well. Just examining the filter for metal is suspect. Best thing would be to do a spectroscopic oil analysis (Blackstone) something I do all the time anyway, but it's too late for that now.

You need to call your dealer and make an appointment to have it in the shop as it will only get worse, not better.

Kubota's are extremely sensitive to overheating and loss of coolant.

Good luck, you are gonna need it, especially if you don't have any warranty. That is a wallet depleter.....lol

 

[5030]

I was bush hogging and thought I smelled coolant, looked at the gauge and it was in the middle of the dial, steered out of the high grass to take a look and before I stopped the engine died.

You should have paid more attention to your nose when you smelled it. Oh well.

 

[big bubba]

do you have K insurance? they cover things like that all the best of luck

 

[Williy]

Can you drop the oil pan and see if the rod is loose if you don't have
a warranty? Maybe you just need to tighten the rod bolts or replace
the rod bearings? Just a thought


willy