New RTV1100 Owner

[Terrawombat]

I found a pretty well used 2010 Kubota RTV1100 on a government auction website and decided to place a bid. I didn't meet the reserve price and the auction ended with me as the high bidder. I assumed that the auction was a lost cause and moved on with my life, but then a week later I received an e-mail asking if I would like to purchase for my bid price. I accepted. Final sale price was a hair over $2500 after taxes, fees and all that good stuff.

The machine has definitely seen better days. I was told that it needed a new engine by the selling party, but they had received the prognosis from their local Tractor Supply store. Considering I have never visited a Tractor Supply that had a service department I was highly skeptical that a new engine was actually necessary.

Once I got it home and charged up the stone dead battery, the engine turned over fine and fired right up, but it did have a very audible knock that got louder as the engine ran longer. I feared a spun rod bearing so I dropped the oil pan and inspected all three bearings. Cylinders 1 and 2 didn't look great, but they didn't look bad and certainly were not in a condition that would cause rod knock. Cylinder 3 looked excellent so I decided to put everything back together, change the oil and filter and focus my attention elsewhere.

After firing up the engine again, I popped the valve cover to see if there was anything obvious underneath. I found nothing. Everything looked to be operating as normal and while I didn't check the valve lash with a feeler gauge, nothing seemed excessively out of adjustment that would cause the knock I'm experiencing.

Next test was while the engine was running, I cracked open each line to the fuel injectors to see if there was any change in operation or tone. Opening the lines to injectors #1 and #2 caused the engine to bog down and shot diesel fuel all over the place, but the knock remained. Opening the injector line to #3 caused fuel to shoot everywhere and the engine to bog down, but the knock decreased. The more I opened the fuel line, the more the engine bogged down, the more fuel hit me in the face and the more the knock vanished.

Now I'm faced with figuring out what this means. I'll keep you all posted.

 

[Jim_S]

Welcome to the Forum!

Glad you found us!

 

[avantiguy]

Welcome, I suspect you proved the injectors are good but as you seem to be comfortable working on the engine, I'd personally pull each piston and check the rod clearance and the piston pins to be sure they are not sloppy as well as the rings.

I'm far from a diesel mechanic but a loud knock is generally an engines way of yelling help before it damages itself.

It could be something hitting somewhere but the knock sounding less offensive as fuel is removed makes me think Rod or Piston pin.

P.S. - Looks like a heck of a buy for $2500.

 

[Terrawombat]

Welcome, I suspect you proved the injectors are good but as you seem to be comfortable working on the engine, I'd personally pull each piston and check the rod clearance and the piston pins to be sure they are not sloppy as well as the rings.

I'm far from a diesel mechanic but a loud knock is generally an engines way of yelling help before it damages itself.

It could be something hitting somewhere but the knock sounding less offensive as fuel is removed makes me think Rod or Piston pin.

P.S. - Looks like a heck of a buy for $2500.

Thank you for the suggestions. My first thought was rod knock as well, which is why I tackled it from the get go. Of course my initial hunch came up short. While I'm not 100% thrilled with the condition of each bearing, they by no means should be making the knocking sound I am experiencing. Granted I only looked at the bottom half, but even if the top half of the bearing was gone, I believe I should see some significant damage on the bottom half of the bearing as well.

My next thought was piston pin as you suggested. That will require quite a bit of tear down of the engine to get to that, but if that is what needs to be done, then it's not the end of world as it can be done in the machine without pulling the whole rear subframe.

When I drained the oil and dropped the oil pan I found no evidence of chewed up bearings which has me scratching my head even more. If a rod bearing or piston ring went bad there is always evidence left behind...

I'll admit, it's not a bad find for $2500 if I can get this engine to stop knocking. What can't be seen from the photos is that the floor pan is completely gone. This rig was used to plow a government facility and they must have used plenty of salt!

 

[aurthuritis]

take the injector from the cyl that knocks and exchange it with a known cyl that doesn't knock. if the knock follows the injector then buy a new set of injectors and proceed. if the knock stays in the same cyl with a different injector then you have a clearance problem in that cyl.

 

[Terrawombat]

take the injector from the cyl that knocks and exchange it with a known cyl that doesn't knock. if the knock follows the injector then buy a new set of injectors and proceed. if the knock stays in the same cyl with a different injector then you have a clearance problem in that cyl.

That's an excellent idea, thank you. I should be able to get that done this weekend.

 

[v10rick]

There are plenty of options for the DIYer. At your purchase price you have plenty of wiggle room.

Kubota injectors are pricey.
The e bay equivalents (Chinese) cost much less and have worked for me without issues.

Engine rebuild kits are about $500. A bare engine block from Kubota is $500.

Unfortunately no aftermarket floor patch panels.

 

[Keifer]

Welcome to the best forum on the net.
Looks like you have a real gem (in the rough) to do some serious work, or work on. Lots of good folks here to help you in time of need.
Come back often and share your progress. Love the photos.
Keifer aka keith

 

[Terrawombat]

There are plenty of options for the DIYer. At your purchase price you have plenty of wiggle room.

Kubota injectors are pricey.
The e bay equivalents (Chinese) cost much less and have worked for me without issues.

Engine rebuild kits are about $500. A bare engine block from Kubota is $500.

Unfortunately no aftermarket floor patch panels.

There seems to be a few shops online that take OEM injectors and rebuild them for about $50 each, which seems very reasonable. I'd rather stay away from the Chinese stuff, if I can avoid it. I work for a manufacturing company and we recently sold a bunch of our products into China and within 4 months it was discovered that they already had copied it and were making their own knock-off parts. Don't really care for their business practices over there.

I did swap injectors #2 and #3 today, but unfortunately the knock remains on cylinder #3. I've got a couple more tests that I want to run, but it's looking like I'll be pulling the cylinder head off and extracting the #3 piston and connecting rod. Good thing is that it appears this can all be done with the engine still in the RTV.

I also had a little bit of help today from my son. He's an expert at pressing the horn button.

 

[Keifer]

Horn button today and before you know it he will be saying, "Hey dad, can I borrow the car tonight. I was going to take Sally to the movie."

 

[bordercollie]

Welcome ! That looks nice! Good Luck ! collie

 

[Terrawombat]

Horn button today and before you know it he will be saying, "Hey dad, can I borrow the car tonight. I was going to take Sally to the movie."

Oh boy - hope that's a ways off. My son just turned 2 and is a keen observer. He must have saw me splitting firewood the other day because he walked right over to my splitting maul and tried to cut a couple pieces himself.

Ultimately my plan with this Kubota is to get it running right, weld all new floor pans in, fix the A/C (compressor is seized) and take care of any other lingering items that would affect its long-term reliability. Once I'm satisfied with its performance, I'll be delivering it to my father on his 250 acre farm as a gift from my son. It should be a nice replacement for the aging Club Car golf carts that he's been using (and abusing) on the farm for the last 10 years. Bonus points if I can find a factory Kubota V4291 v-plow for the thing so my Dad can plow the driveways in comfort.

 

[foxalaska]

The rod cap on the left doesn't look very healthy and the one on the right isn't much better. Did you inspect the upper bearings? Shorting an injector and the noise goes away tells me you have a bearing or crank issue. Shorting takes the load off, thus no knock. Looking at the bearings it's ready for a rebuild. It may not be to late to save the crank.

 

[Terrawombat]

The rod cap on the left doesn't look very healthy and the one on the right isn't much better. Did you inspect the upper bearings? Shorting an injector and the noise goes away tells me you have a bearing or crank issue. Shorting takes the load off, thus no knock. Looking at the bearings it's ready for a rebuild. It may not be to late to save the crank.

I did not inspect the upper bearings based on the condition of the lowers. I agree, the lower bearings don't look great. The photos certainly don't do them any justice either as it looks like there is significant pitting in the far left photo, but none of those circular marks are actually indentations in the bearings meaning if you run your nail across the bearing it won't actually catch on anything. There are no raised or lowered ridges. Based on my experience working on Mitsubishi 3.0L V6 engines, several of which had spun rod bearings, I didn't feel the need to inspect the uppers because I'm confident it is not the source of the knock.

I am confident, however, that your theory is correct in that removing the fuel from the cylinder removes much of the load, which is reducing the level of knock. Due to that, I will be pulling the cylinder head off, removing each piston/connecting rod, performing a full inspection and replacing all bearings that I am able to without pulling the engine from the unit. If I have to pull the engine/transmission from the machine, I'll have to abort the whole project because it will become an issue with my town, so I'm trying to avoid all of that.

 

[Terrawombat]

Haven't done too much over the last week as we got hit with that arctic weather for the majority of the week and then a couple of inches of snow yesterday. Since the RTV is outdoors there was no way I was wrenching on it in 0 degree weather. We are very fortunate we didn't get hit with some of those ridiculous -50 to -60F temps that the upper midwest did.

I did pull off the speed selector assembly from the top of the transmission early last week before we got hit with the cold weather. When I bought the RTV the assembly was completely seized and I could only go from low-range and reverse. I tried soaking the shaft in PB blaster with no luck. I took the assembly to work with me where we have a press to try and separate the upper and lower pin assembly that was seized in the housing and I only made matters worse (see attached photo).

After my mishap, I ordered all new parts from Messick's and they just came in today. Cost about $175 for the parts, which seems like a steep price to pay for a machine that has a knock in the engine, but I'm committed at this point and am very confident I can fix the engine. Got the new speed selector parts together and installed on the machine and I can now select medium and high range!

We've got some warmer weather coming up next week so I'm going to start draining all fluids from the engine in preparation to remove the cylinder head and oil pan so I can extract all three pistons and connecting rods and do a more thorough investigation of the knock.

 

[Terrawombat]

Decided to keep wrenching on the RTV last night and made some good progress. Cylinder head is off and hoping to pull the pan today and extract the pistons. When you crank the engine over by hand you can see the #3 piston wobbling back and forth in its cylinder.

 

[bordercollie]

Great pictures!!! Thanks for keeping us in the loop. bordercollie

 

[Terrawombat]

Great pictures!!! Thanks for keeping us in the loop. bordercollie

No problem - I need to share my progress with someone. I've tried telling my wife but she doesn't seem to care too much.

Engine oil is draining as we speak and the weather is almost up to 40F so I should be able to get the pan dropped and the pistons out. Hoping to have all parts I need ordered from Messick's tonight.

 

[Terrawombat]

Source of knock officially discovered. #3 wrist pin bearing failure. The piston skirt has been damaged and the cylinder wall has a nice sheen to it where the piston skirt rubbed. I did not feel any ridges in the cylinder wall that can't be taken out with a honing tool so the block should be good.

 

[avantiguy]

Sounds like the best possible news. Probably a good times to check the valve seating and you'll end up with a newish engine and nice RTV for an excellent price.