4020 engine issue

Finally got time to tear into our 1967 4020 diesel, syncro, with a M&W turbo that I had asked you guys about a couple months ago. The general idea was that it was a piston with broken rings. Well, we tore into it and all the pistons, liners, and rings are fine and installed in the proper direction (as they came to us as "loaded" liners, with the pistons and rings already installed in the liners)

We also took the head back to the shop where it was done up 2 years ago when we overhauled the tractor, and everything checked out on it.

HOWEVER, when we removed the head, there was a LOT of carbon build up on #1 & #6 piston, head, valves. #2 & #5 had buildup, but not as much. #3 & #4 had basically no build up, the parts were just black, but no layer (up to around 1/32", not actually measured) of carbon buildup.

Before we tore it down, we plumbed shop air into one injector hole at a time to try to ascertain where any leaks would be, and we noted on a couple cylinders there was a lot of leaking out of the valves, usually the intake. So we tapped on the valve with a rubber mallet and we could eventually get it to stop leaking. We checked the springs, and they felt definitely weaker than new ones so we changed them all out. In the end we figured the leaking valves was due to the carbon buildup, but also could have been due to weak springs.

The guy who did the head rebuild suggested that the rings needed to be replaced as the buildup on the head was far more than normal and they were not seating, allowing too much oil up in the combustion area. So we pulled the pistons to look at the rings, however, the rings look good and all were installed in the correct slot and in the correct direction (dots toward the top). So we do not really see a problem with the rings, but we are not exactly experts on the subject.

Just a little recap:
Engine overhauled late 2015
New liners, new pistons, new rings, new valves, reground seats, new valve guides, new bushings on rods
Plasti-gauged main & rod bearings, all checked out on the tight side of allowed tolerance
Engine dynoed, however, PTO clutch was weak and slipped, so we could only run it around 40HP for 1hr. (yes, we forgot the linkage adjustment to tighten it) The transmission clutch has been weak for many years, but we only do light work with it so never a problem, so we knew we could not pull it to break it in fully.

Now we also have split the tractor while we were working on the engine, and fixed the clutch so that we can actually just pull it to seat the rings fully (hopefully).

What are your guy's thoughts on the rings, or what do you think is causing our oil usage in the tractor. It has run 230hrs since overhaul and we have had to add over 2.5 gallons to it in that time.

Sorry for the long post, I just want to be thorough.

Thanks,
Matt

Well 40 HP for an hour is not much of a break in. Did you use break in oil??? IF you put JD 15-40 +50 in it right form the start your rings never seated. If the valves/seats and the pistons all look good than I would replace the piston rings. Deglaze the liners and use break in oil for the first fifty hours of use. Try to not idle the tractor much and load/pull it if you can during this time.

I have seen oil usage like this in tractors that did not get the rings to seat in the first 20 hours or so. I usually use Dynometer to break in a new overhaul tractor. I started doing this 40 years ago when it was common to overhaul tractors during the winter slow months. Guys would take the tractors home and just haul hay out with them until spring. Then the tractor would burn oil as the rings never seated.

Big thing to watch doing is do not use a super good oil during break in. The oil will lube the liners/rings so well they will not wear in. Use break in oil.

Here?s some information on Break in oil . I put my
4020 on the dyno fot 5 hours at 112 hp when I
rebuilt my engine and then took it home and put it
on a moldboard plow for another 10 . I can go all
year And not add a quart of oil
Untitled URL Link

Yeah, I forgot to mention that we have been using Deere Break-in oil the whole time since the overhaul

Matt

(quoted from post at 00:06:48 04/17/18)If the valves/seats and the pistons all look good than I would replace the piston rings. Deglaze the liners and use break in oil for the first fifty hours of use. Try to not idle the tractor much and load/pull it if you can during this time.

Click to expand...

Does that mean the rings have glazed and the only way to seat them now is to replace them?

Thanks,
Matt

Examine the 2nd ring, there should be a
a thin line all of the way around it at
the bottom of it. This is the contact
point where it runs against the
cylinder wall. If the wear pattern
doesn't go all the way around, there is
the problem. This is the ring that
keeps the oil from getting to the top
of the piston. The bottom ring is only
an oil scraper. If that ring is
installed upside down it will pump oil
to the top. New rings can be bad,
especially some of this junk
aftermarket stuff they supply us with
now. The face of that ring is at a
taper, you can see it if you look
carefully.

In the time that you ran the engine, the rings have worn to seat with the cylinder walls. They may or may not have seated properly. After removing them from the cylinders, you will not be able to install them in the exact same position rotationally to seal properly. Install new rings and hone the cylinder walls then the break in process can start over. If everything else checks out the rings could be your problem anyway. I run on a dyno for 3 hours building up to full hp in 1/2 hour increments to help seat the rings. Let us know how it turns out.

(quoted from post at 07:54:00 04/17/18) Examine the 2nd ring, there should be a
a thin line all of the way around it at
the bottom of it. This is the contact
point where it runs against the
cylinder wall. If the wear pattern
doesn't go all the way around, there is
the problem. This is the ring that
keeps the oil from getting to the top
of the piston.

Click to expand...

I will check for that today. I did see that wear line you are talking about on the #1 piston’s 2nd ring, but I will need to check the other 5.

(quoted from post at 07:54:00 04/17/18)
The bottom ring is only
an oil scraper. If that ring is
installed upside down it will pump oil
to the top.

Click to expand...

You are talking the 2nd ring can pump oil into the piston, or the oil ring (3rd ring)? We could not find any marks or anything to tell us which way the oil ring went in, leading us to believe it does not matter. However, the 2nd ring had 2 dots on it that were located on the top, as installed, on every piston.

(quoted from post at 07:54:00 04/17/18)
New rings can be bad,
especially some of this junk
aftermarket stuff they supply us with
now. The face of that ring is at a
taper, you can see it if you look
carefully.

Click to expand...

We got our kit from Deere, on the recommendation of a neighbor who has done a few before.

Thanks,
Matt

My shop is telling me that the Deere break in oil has changed. He wants me to start adding a Lucas break in additive with zinc. Tom

Have you checked the turbo it can leak oil by the seal on turbo shaft into air intake. The M&W RAJAY turbo has few parts to repair turbo other than a seal kit.

Yes the 2nd ring. I got educated
about about the rings when I had a
warranty issue. The company had a batch
of that second ring that wasn't right.
The engine was burning oil right from
start up because those rings weren't
made right. Like I mentioned before the
3rd ring is a scraper. If they look
good I would be looking at the turbo as
previously mentioned.

(quoted from post at 10:12:39 04/17/18) Have you checked the turbo it can leak oil by the seal on turbo shaft into air intake. The M&W RAJAY turbo has few parts to repair turbo other than a seal kit.

Click to expand...

We checked it with it running soon after we had overhauled it, and it did not blow any oil out the outlet of the turbo on the the intake side.

There are 3 sections of pipe from M&W and then the intake manifold between the turbo and the head, the first 3 are dry but there is a light film of oil in the intake manifold (you can feel something on your finger but not see it other than your finger is a little shiny).

Also, what is the consensus on the rings, if they look good reuse them or not? We can hone the liners no matter what.

Thanks,
Matt

I checked all the 2nd rings, they all have a wear line that goes from the bottom up to about halfway up the outside of the ring.

The top rings have a wear spot on most all the surface, just a tiny line at the top and bottom that are not polished by wear.

Matt

Another question is the positives and negatives of just removing the turbo from the tractor (thus removing it as a variable), as we do not use it hard, just light duty applications.

Matt

If it was mine I would deg-laze the cylinder and reuse the rings. Those may be tricky to get back in the cylinders without breaking a ring. They come loaded in the cylinders for a reason.

The best way to find where the carbon is coming from is to look where it is not. There should be a "washed" area at the source of the excess fuel/oil. The edges of the pistons will be washed clean if the oil is coming up past the rings, same with excess fuel or oil elsewhere.

I have seen more than one 4020 with the MW kit on it that had the return oil line from the turbo routed wrong. This caused oil to back up in the turbo then out the pipe. This line needs to head down without any big curves or flat spots. Al

Synthetic oil? You can't use it in fresh overhaul.

You only use the break-in oil for the first fifty hours or so. Not for 200 plus hours. That alone could be your oil consumption issue.

I was just informed from a John Deere dealer service tech That I should run breakin oil for a 100 hours. Then drain and refill with breakin oil and run another 100 hours. 200 total. This is on a 4020 feed grinder tractor.

We have decided to deglaze the liners and put the pistons back in with the same rings, as they look fine.

Whenever the weather here in NW IA straightens out and the fields dry up, we are going to take it out and pull it hard for most of a day, at the minimum. Then we will see if actually breaking in the engine takes care of our problem along with the new valve springs.

I will post back afterward to let you guys know what happens.

Thanks for the help,
Matt