YM336D - Started knocking loud while tilling

westcliffe01 · Mar 12, 2012

Were you able to figure out the condition of the small end bearings in the rods ? I had a Toyota 22RE where all the small end bearings were toast. It had a weird sound for a gas engine.

The timing of the diesel pump can have a big impact on how it runs. Retarded and it may start nice but have no power. Too advanced and it may knock like crazy. Any idea if anyone had been poking around inside the diesel pump ? The metering system is typically driven by a rack and if one of the plungers is out of sync it will not get nearly the right amount of fuel.

But working on the pump is not something to be taken lightly.. I think, provided you can remove the injector nozzles, you can have them tested. They are mechanical parts that see lots and lots of cycles and are in a pretty extreme environment so they do wear out, clog, break etc. The back pressure of the spring in the nozzle (cracking pressure) is a key part of the timing since it determines when fuel starts flowing and how it is atomized. I don't think they are too expensive and by having them checked you can pinpoint the problem. A new nozzle is a lot cheaper than an injection pump.

Garybake · Mar 13, 2012

Domush, I am only at post #36 and can see your head gasket was shot on the left of cyl hole #2. It appears you may have been burnning antifreeze from the cleaned off piston top. Antifreeze smokes white. Water in high compression deisel combustion will expand as steam and in knocking loose carbon and discoloring your cylinder below TDC combustion area and cause excessive blowby or crancase vent pressure. It can also cause a piston skirt to collapse which can cause knock especially when cold (before skirt expands fully towards wall) and may foul the injector over time sitting damp.
Just my $.02 worth as your last posts seems it is not resolved. I will try to read rest of thread tomorrow night. I may find by the end of this thread I am talking foolish. (I can handle that if on chance I am not).

Neat 1500 · Mar 13, 2012

usually if an engine that has just been rebuilt is shut down midflight then tried to be restarted it is extremely difficult to get it to spin at a speed which it will restart. you will have to wait for it to cool before attempting to start it again. i found this with several petrol engines i rebuilt, let alone a high compression diesel. even 2 batteries in parrallel wouldnt turn one of them over fast enough, it turned out to be a ripper engine once it was run in so dont get all bent up over it just yet.

bruce1966us · Mar 13, 2012

It sounds pretty normal to me. Your timing might be slightly advanced though.

Car Doc · Mar 13, 2012

Domush,

Quoting you- "it is a mostly solid, two bladed ring with a bunch of holes between them and that weird spring thing on the inside."

So its one piece with a spring in behind it rather than a 3 piece? A 3 piece where you put the expander in and then wind the scrapers in one at a time? EDIT: I went back and blew up a pic of #2 piston and I see its a solid so disregard the folded ring theory thats a good thing!

Did you have trouble getting any of them in smoothly? If so that would be the one I would be looking up into the sleeve with piston up and looking for a scratch forming in the bore. Fact all of them are suspect at this point but any known ones pay close attention too!

I am just not remembering what mine was so pic of an old one would be nice so we can file the folded ring theory.

To me (also as noted by 284) it still has a hitch in its get along while cranking meaning a low/high cylinder for some reason. That doesn't 100% mean anything is wrong with fresh rings old pistons but it is odd I did not expect to hear that. Praying it isn't a bent rod.

How does the fuel flow from #2 injector line at both ends equal to the rest critical info here? hth

edit: You can do your own pop testing just pull the injectors re-attach them upside down and crank it. Switch a bad one to a line that is working to isolate injectors/plungers you have at least 2 known runnable now. May not be perfect but thats not the concern at this point.

Compression test also if you have the tool.

Oh btw it wont make any difference what order the pistons went in however the orientation of front and back is on most engines though. fwtw

edit: one exception is if one was bent and got in another hole the miss will follow and if there is still a fuel problem well you can add those odds up.

edit #2388.5 Rod checking from outside the engine.

Just throwing this out use it if you can but with the injectors out and the pre-chambers also a person who was very careful and accurate with their measurements could feasibly find a bent rod w/o tear down.

This would be the procedure-with pre chambers all out and a socket on the crank bolt and a long screwdriver or rod turn every piston slowly up to TDC (a dial indicator would be so nice for this) and mark the rod in such a way as the same measurement could be made in the next cyl if you are following me? Any measurable difference and that piston would need to come back out. Recheck and recheck to make 100% sure there is a difference and go from there.

One more thing if you still have all the old bearings lay them all out side by side with the bearing surface up twords the camera and take a pic I can tell you if there is a bent rod by that and they dont have to be in any order either unless you still have them in order that would be real nice!

clemsonfor · Mar 13, 2012

Domush said:
I have had a very slow coolant leak (1 cup every 1 hours or so) above my water pump which I have not been able to stop. I wonder if it is caused by a water blockage, and the pressure is building until it leaks? Probable? Wouldn't that affect the temp gauge reading, though?
.

Thats a lot if you ask me!! Is the bearing bad, does it come out of the weep hole, i guess not as thats easy?

Kyle_in_Tex · Mar 13, 2012

Great thread, well documented. Lots of advice. The thing I've learned from this is to change my dang oil.

I believe the sludge clogging your pickup is what put the final nail in the coffin.

I haven't read your previous threads where you fixed it up, but I can see the before and after pics. Somebody somewhere didn't do jack squat for maintenance on this poor tractor.

scoops · Mar 13, 2012

I've had two 3 cyl yanmars, and they both sounded like yours.

I don't have a trained ear, but I listened to that video, and yours sounded just like the ones I had.

As for it shutting down on you, did you verify you are getting enough fuel?

jonyyuma · Mar 13, 2012

Domish, I had a bad injector in MY Mercedes... It put too much fuel into the cylinder and made it knock..Plus it can puddle up on top and make a lot of noise when it runs...Glad you made it thru the cylinder caper...

Car Doc · Mar 13, 2012

Garybake said:
Domush, I am only at post #36 and can see your head gasket was shot on the left of cyl hole #2. It appears you may have been burnning antifreeze from the cleaned off piston top. Antifreeze smokes white. Water in high compression deisel combustion will expand as steam and in knocking loose carbon and discoloring your cylinder below TDC combustion area and cause excessive blowby or crancase vent pressure. It can also cause a piston skirt to collapse which can cause knock especially when cold (before skirt expands fully towards wall) and may foul the injector over time sitting damp.
Just my $.02 worth as your last posts seems it is not resolved. I will try to read rest of thread tomorrow night. I may find by the end of this thread I am talking foolish. (I can handle that if on chance I am not).

You are on the right track no doubt I pointed the head gasket out also good catch!

I believe by his skirt measurements they are fine at least they are consistent put it that way

he does however have a bit excessive top ring groove clearance which is what it is a repair not a new engine it will be fine he did the absolute necessity parts the head and sleeves fuel system may be next. :thumbsup:

kenmac · Mar 13, 2012

Don't know what's wrong. But, something is. It takes too long to start ( longer than mine). The knock never seems to go away. Mine will knock when I first it & leave it at low idle. Once it warms up or I idle it up the knock goes away. There also seems to be a good amount of smoke comming from somewhere ( can't tell from the vid. where it's comming from). I.m sorry to say but, I think your going to have to go back in. you have done alot of work already. Bummer

Domush · Mar 13, 2012

kenmac said:
It takes too long to start ( longer than mine).

The injection lines were still empty, so it had to fill them. I don't think that part was abnormal, as it has happened before when I removed the fuel lines.

The knock never seems to go away. Mine will knock when I first [start] it & leave it at low idle. Once it warms up or I idle it up the knock goes away.

I'm beginning to wonder if the knock and stall is from the fuel injection being too far advanced. Now that the engine has better compression, I wonder if advanced ignition is stopping the pistons, stalling the engine. That would also explain the knock. After all, that knock was there before it got bad enough to rebuild. I wonder if retarding the timing is the fix for all of this.

There also seems to be a good amount of smoke coming from somewhere

I've never had new rings and cylinders, so I wasn't sure if that was simply the rings letting oil passed until they seal up fully. The initial smoke at start is likely from the oil I lubed the cylinder walls with when installing the pistons.

Either way, I bought some plastigauge today and will plastigauge the rod bearings seeing as I have it open. I really am starting to think it may be advanced timing. I'll check the lines for flow tomorrow

Domush · Mar 13, 2012

clemsonfor said:
Thats a lot if you ask me!! Is the bearing bad, does it come out of the weep hole, i guess not as thats easy?

Yeah, it just recently starting leaking that much (while running only). When I first got it I thought it was because the gasket was bad, but I made a new gasket and it just kept leaking and out of two different pces, which now leads me to think the pressure is up in that area.

kenmac · Mar 13, 2012

Domush said:
I wonder if retarding the timing is the fix for all of this

Never fooled with timing on a diesel. I thought the only way to adjust is shims at the injector pump

Domush · Mar 13, 2012

kenmac said:
Never fooled with timing on a diesel. I thought the only way to adjust is shims at the injector pump

It is. When I bought the tractor, one of the injector shims was crimped, which means it was removed at some point. I wonder if it is missing a shim from before I got it. I can't take anything on this tractor for granted, obviously the PO didn't care if it lived or not.

5030 · Mar 13, 2012

Injector pump timing can be adjusted a number of ways, internal shims, by physically rotating the pump (common with rotary type pumps) or by gear train under the front cover.

Usually, the gear train will have reference marks that line up when everything (camshaft, crankshaft, pto and fuel pump) is in correct relationship to each other...........

Some pump input shafts are splined and the spline mates to another spline cut in the fear that resides under the front cover.....

A shop manual with drawings/exploded views would be helpful.....

winston1 · Mar 14, 2012

Not meaning to imply timing is your problem. Just sharing some specs. I believe your injector should pop at 25 degrees before top dead center. 1 shim equals 1 degree. If mark has gone by pointer-remove shims. If mark has not reached pointer-add shims. Domush, I commend you, you are a man of patience. :thumbsup:

Car Doc · Mar 14, 2012

I am still wondering how much fuel is coming out of #2 at the injector?

I would definitely do a compression test (remember the hitch?) and dont worry if the pan is off there is plenty of oil on everything. Do this before plastigage if there is no side movement in that tight rod otherwise there wont be enough oil plastigage needs dry crank/bearing so make sure to oil it after checking it.

And you are 100 thousand % sure the caps are on right.

That way you can make an educated decision as to what the next logical step is. I hope my methods are soaking in there is something to my madness.

All things considered I almost never miss on my diagnosis when its hands on this is fairly difficult online.

But as long as steps are taken in order I do this every day year after year on very complicated vehicles this tractor is simple as pie. good luck hope that helps :thumbsup:

The timing is and I have not done one yet just researched it because I am 95% my timing is fast also. Anyway put a short fuel line on the #1 plunger installed like a "J" pointed upwards. And you slowly turn the crank and watch the fuel just start to pour over the top of the tube and at that point you look at the timing mark on the front cover/crank pulley. (and I believe Winston is right on w/25 deg from my memory anyway

) hth also

Garybake · Mar 14, 2012

Domush, My apologies for not being back online for you sooner. (Yesterday was a Crdiologist Visit From H3ll. Then Primary care and then Hospital)

I tried to read all posts and found mind wandering on my issues but realize all the great intelligent help you have gotten. Now she is built up it sounds fine. (Not new)... My experience tells me you have one piston skirt that when cold is stiff and slightly collapsed/oblong cymetrically. Once warmed it will expand and not be such an issue Noise/blowby/little smoke. It takes time to warm to expansion. I hope you had your cyl head milled flat as I suspect it was severly overheated before you owned and distorted. This is also why coolant pump shaft seal started leaking as easy escape of compresion stroke cyl pressure in water jacket. On intake stroke hot pressurized water jacket fed cyl (discolor of exhaust port on 2.) You did a great job and had great help. I think you are worried and need a confidence boost to just go work that thing and get some breakin hours. It sounded great and was getting quiter towards end of clip. Did seem like awfully long crank time so fuel delivery may need tweaking.
Pat yourself on the back and run the snot out of it watching that temp gauge and then change oil/filter. Will run hot breaking in so use a coolant (not water) to prevent steam pockets. Sorry I was not more help

.
You have a lot of great intelligent support just do not doubt your work you did good, it will run fine give in some breakin time.:thumbsup:

Go to VID on post 36
Listen to 50 second mark of video and then 2:30 Mark and switch between them.