YM336D - Started knocking loud while tilling

[Domush]

Okay, she is back together. Only the second time I've gotten to use my new torque wrench, so that was nice. It started pouring rain once I finished up putting the drive shaft back on.

Did you look at the upper bearing shell that's under thrust too... Or just the lower half?

I only checked out the lower bearings. I figure if there was any damage to the top ones it would bleed over and leave traces on the crankshaft as well. Too late, now, anyhow

I cleaned the oil pan, lubed the bearings before assembling them, cleaned the pickup screen (man was that caked on) and replaced the oil and filter. I haven't cut open the old filter yet, but it sure is heavy, even after draining it. I can only imagine how much of that gunk got caked into the oil filter as well.

PS: If you haven't bought oil lately.. don't! What an absurd price! $4/qt now! It cost me $25 just in materials to give my truck an oil change! Unbelievable.

Once the rain lets up I'll head back out and give it a crank. It barely started the other day, so hopefully it has enough juice to at least start up a few more times.

 

[Car Doc]

Yeah oil prices that is a sore subject alright!

Now days a guy would need to cash in an IRA to buy a 55 gal drum. I used to buy and keep 4 on hand at a time (engine oil, ATF, anti-freeze,90wt) but those are just memory's now.

 

[Domush]

Well, I started it up and it still knocks really loud, though the oil pressure is nearly 60PSI, now. Obviously the oil passageways were horribly clogged. Now I have to pull the pistons to check out the rings and sleeves, as I think that is where the knock is originating from (by ear). I also notice there is now smoke coming out of the crankcase breather tube which never happened before.

I started removing stuff to remove the head, but I can't get the head bolts to budge at all (any of them ), and to boot it is one of those days where the weather can't make up its mind. I'm doing this all outside, as the tractor doesn't fit in the garage (too tall with the canopy) and I don't have power in there yet, anyhow.

I was afraid fixing the oil was too easy a fix. My luck isn't that good.

Any tips on getting the head bolts to loosen? I tried PB blaster, but they are painted twice over, so they are pretty penetrant proof at this point. I don't own a 1/2" breaker bar. Would using a breaker bar be safe or am I risking breaking off a bolt? I really don't want to have to buy a new impact gun for 6 bolts.

 

[Car Doc]

Man that sucks I am almost sure the knock is not the rings and pistons or the crank (least from the clues you gave so far) the smoke from the crankcase is a clue I think.

How are the valve guides and all that rocker train? Grab a valve spring and wiggle the valve a real bad guide will blow by also a cylinder with valves not opening will too, the combustion has to go somewhere, busted piston or busted rings will also blow by and knock however. (I just dont see it in this case though fwtw)

I would check some of this stuff before tearing the rest of the way down and btw those bolts are really tight it will take a long bar and a hammer on the end of the bolt possibly. Go one way and then the other try tightening them a bit first sometimes works also and go back and forth quite a few times before giving it all.

I use an air hammer and try not to beat it to the point a socket wont fit thats a trick not a for sure thing fwtw.

edit: Sounds like its too late to try this but I always like to find clues before I tear into things (just because) my suggestion would be if it still ran start cracking injectors and see what that shows.

 

[tcartwri]

As was mentioned, a bad injector will make the engine knock like a bstd.

 

[Domush]

Well, I took the head off anyway, as I'm quite sure the #2 rings are shot anyhow, as it smokes up a storm when running, so if I'm digging this deep, I might as well fix it fully.

I didn't find any unique valve wiggle (they all wiggle roughly .5mm side to side).

Something to note, a while back I turned the crank by hand in order to test the compression of each cyl and #3 had awesome compression, #2 had very little and #1 had an average amount. It was obvious from that #2 was the cyl causing the massive smoke, although #1 may have been contributing a little. You'll notice in the photos that #2 def has an issue of some sort.

I didn't notice any issues where something was escaping to a different passageway. All seals looked unbroken, but I'm hardly an expert at this.

#3

#2

#1

#2 close up

#3 close up

#2 and #1

#3 and #2

#3

#2

#1

So.. what do you think? #2 is odd in that it has black until about 1/2 down the cyl where the other two have a clear transition about 1/2" down from the top.

If anyone wants to see hi-res versions of these, you can go straight to my picasa account (they are 5MP photos)

 

[tcartwri]

That engine sat somewhere for a while. #2 is done like dinner. Amazed that the rings are still in the piston.

 

[Johnp33]

To clean out an engine, and I did it for a living use ATF dexron 3, you can overfill it and even work it with it in there, 10 minutes to 1/2 hour, I use about 20% ATF, it really works and it is cheap and something that has other uses.
The engine you have, a complete overhaul or replacement in your future.

 

[Car Doc]

Well that motor needed torn down thats the bottom line. I cant see it real good but the head gasket fire ring around the middle cyl looks awful black that means its not sealing and may be what washed the piston down but at this point its over and done rebuild time. Its not the first or last dead horse I will ever kick in the ***.

 

[90cummins]

Hard to imagine how a person or persons could damage & break so many parts of this tractor.
It certainly was severely beaten & neglected.

You sure have your work cut-out for you!

90 cummins