Hello and Merry christmas everybody. I've finally gotten around to taking my older 977H D333 engine apart to try to fix it. It wasn't firing on all cylinders and had tons of blowby. The #3 piston seems to have very worn rings, it is coated in wet oil and lots of coking. Then there's the #5 piston as you see in the picture... It is just full of pits and holes. There still seems to be compression on this cylinder because there's very little wet oil in there but tons of coking on the head. I have 2 new pistons with rings and 6 new injectors that will be going in tomorrow. Hopefully this will fix the problem. Is it a good idea to run a cylinder hone down the liners while I have the pistons out? The #3 cylinder looks quite glazed... Is there anything else I should look for while I have it apart? I suspect the injectors caused the problems on the #5 piston as there's a whole mishmash of injectors in the engine, none appear to be the right part number for it... There was also no other debris in the cylinder...
Give the liner a tickle with a hone for sure, if not the rings have nothing to easily seat into. Make sure you put some tape or rags or plastic to keep honing goo out of the oiling galleries on the crank if youre not pulling the liners.
The pitting is probably from water entering the engine most likely through the exhaust.
Spitz, The two new pistons and rings -- if you are not also putting new liners in, be sure to check for a ring groove around the top of the cylinder. You should consider cutting the ring groove out if it exists. If you aren't familiar with the term ring groove, its the "step" created at the top of the cylinder, under the carbon buildup, by the ring wear on the cylinder.
Thanks for the replies guys! I've been making some progress, but of course over Christmas there are also other family things to do so I haven't got as much done as I was hoping but it's going back together now! I did hone the cylinders a bit and there was a definite ring groove on the #3 cylinder, the #5 was not as pronounced... Somebody has been in this engine before and put a damaged piston in the #3 hole as you can see in the picture... At least I think it was damaged because I couldn't find any trace of the missing piece anywhere in the engine or the oil... The second ring was in many pieces, thankfully they all came out with the piston and didn't do any damage whatsoever to the liner! I didn't take any pictures of the liner after cleaning with the hone but they both looked like new! Now I'm in the process of putting everything back together... I hope to have it running again in a day or 2 if nothing else comes up in between. I'll keep everyone posted on progress! Thanks again for the replies. Merry Christmas everybody!
You should have the tabs on your wrist pin snap rings down toward the rod rather than side ways....looks like you already installed piston..
If by "missing piece" you are talking about the hole between the ring groves on the piston in the second picture that's caused by the broken rings. Combustion gases act like a blow torch and burn the metal away. I would suggest removing all the pistons and check them while you have it down this far. If they look good you could at least replace the rings. I would hate to think you get this back together and have the same problem again in a week or two.
I didn't know that they should be like that... They were all in random positions when I took them out... Yes, that's the piece I mean... I was thinking of taking the whole works apart but I don't have the parts here and I have to have the machine out of the shop by Saturday at the latest so unfortunately I won't have the time to wait for more rings, etc... But I do agree that I should have taken them all out..........
Do you mind if I ask what the parts ran you?
Sure! 2 pistons with rings, a head gasket, 6 new injectors and a few other little seals and things came to just north of $400 including shipping to my sister's work.
Well I just thought I'd give a quick update... I got everything put back together and running great! No more huge cloud of smoke and all 6 cylinders fire! She runs very nice and smooth now! All I have to do now is make the bucket I have fit and put it to work! One thing I would like to ask the experts is what engine the injectors I found in there are actually for... Two were correct for the engine, the others were cat part numbers 7m4601 and 8N5986. I'm sure they are what led to the demise of the #5 piston...
8N5986 is a former number for 3S6638 which is the correct one for your machine (unless it's a very late serial number). 7M4601 however shouldn't be in your tractor. It is for a D353 (powering the early D9s, for example) and D379, D398 and D399 which are 8, 12 and 16 cylinder marine and industrial engines.
Hmmmm... Maybe I should've kept those 8N5986 injectors in that case... Here's a video I put together of how it ran before, some pictures of the thing apart and how it runs now... https://www.youtube.com/watch?v=LhPpOszRbjo