Oil & Fuel Small pieces of metal in oil

[highvolt1]

Just bought the YM 1700 and changed oil. The previous owner must not have changed it in a while because it was nasty. When pouring used oil in another container, I found several small pieces of copper colored metal that came out of the pan. I removed the pan and found a few more small pieces, but everything looked good and tight and I did not see any damage on the rods, bearings or piston skirts. I cleaned and re-installed pan, added oil and it runs fine as it did before I changed oil. It is not down on power and I see nothing out of the ordinary.
In the postings back in 2005 a reader found metal particles but ran the tractor several more hours. After several readers advised him to check things out he carried it to a dealer who found a broken crank. I would expected he would have had more knocking or clanking with a broken crank, but he didn't state that was the case.

Has anyone else seen metal particles and what do you recommend I do?

 

[kenmac]

Copper material would be an indication of rod, main bearing material. I would pull a rod / main bearing cap & inspect

 

[DieselPower]

If you have copper in the pan then you most likely have a problem. As kenmac mentioned pull the main and rod caps and check the condition of the bearings. It could also be comming from the cam bearings, a little more difficult to check. Not familiar with Yanmar so I'm not sure if they have other bearings in the gear case that may also have copper based bearings. Better to spend some time and money now and find the source of the copper then to wait and spend a whole bunch more in a month or so when it locks up.

 

[California]

Has anyone else seen metal particles and what do you recommend I do?

Did you buy this from a dealer? If so, I would take it back. If that's impossible then I would do as suggested, examine the bearings and repair as needed, before putting it in service.

 

[MJPetersen]

Remember that the mains will be most worn in the cap side, but the rods will be most worn in the rod side and not the cap side. If you pull a main cap and it looks good you do not have to worry about the top it will be OK. It is the rod side of the rod bearings though that get the most pressure and therefore, wear.

Mike

 

[kenmac]

If he has trash in the oil system( which I'm sure he does now) he could have wear every where, even in the oil pump gears. I have taken car engines apart that had the oil pump gears eaten up from metal particles in the oil system

 

[chriswheeler]

Sure you could pull the caps on the rods and main bearings and look for damage, that's one way. You could go and get a oil sample kit ( cheap ) turn in the sample and let the lab tell you before you start doing a tear down. I would not run it until looking under the caps on the rods and mains. These things are at least 25 years old and you expect to see traces in equiptment that has run this long. Just don't want to run it past a point where rebuilding costs more than it had to. Example, having to by a new crank shaft. Oil sampleing is well worth the price on almost any engine.
Chris

 

[Underwaterdog]

Normal wear and tear is comprised of particles far too small to see with the naked eye. Copper colored could be bearing material (babit) or bushing material, and could have come from any number of places, crank-rod bearings, an oil pump bushing, timing gears, etc. It sounds like something wasn't getting lubrication. Its harder to hear a knock or rattle in a diesel than a gas burner. Do check those rods and mains as MJ Peterson outlined, because a rod or main could have spun. Locating it now can save money as opposed to continuing to run it. The bearing material is intentionally softer than the crankshaft. As far as a broken crankshaft, I have seen gas engines continue to run with a broken crank, and the only noise is a rattle. Since the crank is cast, it doesn't break evenly so both ends mesh and continue to spin. I have seen a number of Ford 351's from the late 70's early 80's era with broken cranks that continued to run and the only indication was rattling.

 

[highvolt1]

Thanks everyone for your recommendations. It looks like I have some work to do. I am pretty mechanically inclined and have worked on alot of engines, but never a diesel or Yanmar.
Is checking & replacing main and rod bearings a simple thing thing that I could possibly do?
Have any of you had the opportunity to do this work before or did you let a dealer preform the work?
I bought the tractor from an individual that needed money and I got it for a great price. Even if I have to put a little money in it, I will still come out good.
The tractor looks and runs great and everything works, but I am concerned with these metal particles.
Thanks Again

 

[svcguy]

There is no reason not to perform all engine work yourself with the help of the right manual or at a minimum, engine specs for clearances, torques, etc. If you have experience with gas engines, you are fine. There is virtually no difference between gas and diesel as far as an overhaul or rebuild would be concerned. It is best however not to disassemble your injection pump.

I would suggest you drop the pan and look at the rod bearing surfaces first. The possibility of the rods being good and the mains being bad is unlikely, possible, but unlikely. When you drop a rod cap, immediately slide a piece of rubber tubing over each of the two cap bolts. This will prevent the threads from damaging the rod journal as you turn the crank or push the rod up to examine the upper rod bearing surface.

I am not sure what you are referring too as small pieces of copper. 1/64th of an inch? Keep in mind it is not unusual to see a very fine suspended 'dust' glittering in the sunlight after changing old, dirty oil. Although not good, it doesn't necessarily mean your engine is on it's last legs or in need of major repair. It does mean that it is worth dropping the pan or bottom plate to clean the sump and pickup tube filter, a recommended, scheduled procedure with the older Yanmars.

If you do pull the caps, check the clearance with plastigauge just for peace of mind. I wouldn't obsess about your engine, it probably is fine, but it would be a shame not to take the time to confirm it's condition.