Tractor might be shot - now working on compression testing and have questions

[Omnipotent]

OK, so decided to go test #1 and #3...both test at 440 PSI, so everything is working and the blown head gasket theory seems to be confirmed. Will be removing head and getting new cylinder, intake and exhaust gaskets and will report back when complete. Probably will also get the head tested for runout to make sure it's still in spec, might be able to do this myself but we will see.

Any other suggestions advice from seasoned tractor or diesel mechs please chime in if I'm going down the wrong path or you have suggestions on other items I should be checking/replacing while I'm in the top half of the engine.

Thanks

 

[WinterDeere]

Wow... never seen a zero! With other cylinders at 440 psi, you'd think even a blown head gasket would register something, albeit real low.

Hopefully that's it, though. Anything else that yields low compression is worse.

 

[RayIN]

Never seen zero;
With a zero psi, I'd suspect a big hole in a piston, or piston top jerked off.

 

[1Mech]

Or a dropped or bent valve, probably exhaust, but that should have made some unusual noise!
Regardless, looks like the head at least is coming off.

 

[Williy]

Don't forget to replace the head bolts if removing the head

willy

 

[Omnipotent]

Don't forget to replace the head bolts if removing the head

willy

Thanks, didn't know this was a thing, just figured like

Or a dropped or bent valve, probably exhaust, but that should have made some unusual noise!
Regardless, looks like the head at least is coming off.

Really hoping not, was going to do a leak down test, but decided to just dive in since the head gasket was already a known issue...today's the day to find out.

 

[RayIN]

My MF 135 had head studs instead of bolts. After 53 years the studs were rusted to the head. I had to soak them with PB Blaster every time I was near the tractor for a week.
Then I still had to use a bar to pry the head off the studs.

 

[hayden]

How old is this machine?

 

[Omnipotent]

OK guys, back and not the best news, bent rod but terrible damage to the #2 piston and cylinder. I have no idea what metal caused this, as nothing in the top half dropped, valves, springs, retainers, rods...I mean it was all there a together. My best guess at this point is the top ring on the #2 somehow floated on top of the cylinder and then got crushed/melted into the piston and damaged the head.

PICS

As you can see form the pics it's quite a bit of damage and I now have to remove the whole darn motor and I believe that is going to require me to break the tractor in half (looking into this so please let me know if you don't believe this step is necessary) and then open up the bottom and see exactly how much worse it gets.

Needless to say last night turned into a 12 pack night as I drowned my sorrows, but the work continues and then we will see ultimately how I will address it all.

 

[dodge man]

For some reason I don’t think it was the ring but possible. It obviously sucked something in though.

 

[Racer4]

Wow, that’s some serious damage! Possible that the bottom part of a valve guide broke off and fell in? I’m really curious as to what got in there.

 

[dodge man]

The only thing I can think of is a part of injector or glow plug. Without seeing the engine I’m not sure what else in the intake would cause this. You can tell something got in there and hammered away.

 

[dodge man]

That looks like an indirect injection engine with the pre chamber that contains the injector and glow plug. I bet something in there broke off and fell in.

 

[hayden]

Or something got sucked in through the intake....

So you can't drop the oil pan, remove and replace the piston and rod, and put it back together without splitting the tractor?

I'd guess that head needs to be replaced. All those craters will mess up compression, and I'd guess they are too deep to plane the head down.

 

[Carl_NH]

Or something got sucked in through the intake....

So you can't drop the oil pan, remove and replace the piston and rod, and put it back together without splitting the tractor?

I'd guess that head needs to be replaced. All those craters will mess up compression, and I'd guess they are too deep to plane the head down.

This is what I would try first - and probably need to hone the cylinder if its scored too,

 

[edgar10937]

Pull the pan get the piston and rod out, find out what caused the mayhem, then plan course of action until you know the cause you are wasting energy.
Run the piston to the bottom check cylinder bore,
Head can be fixed needs to be crack checked along with any other work, many are running with dings in surface just be sure no sharp edges to get hot.
Does it have a turbo, heater in the intake like dodges?
Edgar

 

[WinterDeere]

I wouldn't be pulling piston and rod until after following dodge man's lead, and looking for a broken injector or glow plug. You can run the piston to the bottom of the bore to check the cylinder walls for damage from whatever object got in there, without pulling the piston.

Maybe you will need to pull it, in the end, but I'd not be jumping to that until proven necessary. There will be ridges to get those rings past, and at a mininum you'll be doing ridge cutting and honing to put the thing back together with new rings.

 

[Omnipotent]

Thanks all, didn't really think about working from my back, since I'm only "concerned" with #2 this approach does make sense.

As for the "metal", I've torn the head down as far as needed and nothing is missing, there is a bent rod on the #2 intake, so it is confirmed (at least by me) that the metal came into the intake but still don't know from where as everything is accounted for. I did run it back through the intake and up to the air filter, and nothing looks damaged, inside of intake looks "perfect". I did examine #2 glow plug and injector (as well as 1 and 3) and again they all look identical so I'm still stumped.

I am leery to replace and put back together until I at least have an idea of what caused the damage, but I'm just not sure where to go next...other than the oil pan so that will be next step (much better than separating tractor).

Also, going to bring the head to a machine shop and see if they can deck it, but some of the pitting looks pretty deep (relatively speaking) so not sure they could take off enough to make a difference.

New head is 2K, although on Ebay they have Chinese heads for $750...but are they crap or is it the same folks making the Bobcat/Kioti head anyhow.

Time will tell

 

[hayden]

So it's a valve push rod that's bent, not a connecting rod? That was unclear. Regardless, there is no way I'd reuse that piston.

Wait, that cylinder has zero compression, right? Why not? Are the valves not closing properly? Was the head gasket intact? If so, the those valves must not be seating correctly to not hold compression.

 

[dodge man]

I wonder if the valve seats are hammered also causing no compression.