oil additives (Yanmar engines)

[lawrence dennis]

My 1-GM-10 (C), one-cylinder, 9 hp diesel engine on a 1982 CD 25D has recently started using oil excessively (1 1/2 qts. in 25 hours' running). I have checked with local diesel-service experts and also the Southeastern Yanmar distributor. They don't recommend use of any diesel oil or viscosity-enhancing addtives. Their only suggestion is the use of higher-viscosity oil than the SAE 30 recommended in the manufacturer's specs - SAE 40 or even 50 wt.
Anyone have any contrary or similar experiences or suggestions short of a ring job?



ldboats@aol.com

[Bob Luby]

I just got back from Mack Boring's 1 Day diesel course, which I reccommend highly.

Are you getting smoke out the exhaust? Have you ruled out leaks as the problem?

Could you possibly be overfilling the engine? If you are, the excess oil will be blown out and this will look like engine damage. (Smoke out of the exhaust.)

Of course - a little knowledge can be a dangerous thing!



Rluby@aol.com

[Bob Miller]

Make sure that you are using the right oil. Yanmar suggests using a 30 weight with a CD detergent package. Using a CD type oil is more important than the viscosity. The Yanmar labeled oil is the right stuff even if it seems pricey at about $ 2 a quart. Hope this helps. - Bob M.



millerfam5050@worldnet.att.net

[Brian]

you might want to check the oil pressure sender for a leaking seal.

My 1-GM-10 (C), one-cylinder, 9 hp diesel engine on a 1982 CD 25D has recently started using oil excessively (1 1/2 qts. in 25 hours' running). I have checked with local diesel-service experts and also the Southeastern Yanmar distributor. They don't recommend use of any diesel oil or viscosity-enhancing addtives. Their only suggestion is the use of higher-viscosity oil than the SAE 30 recommended in the manufacturer's specs - SAE 40 or even 50 wt.
Anyone have any contrary or similar experiences or suggestions short of a ring job?

[Scott]

If your engine starts well when cold, the rings and compression can't be too bad. Unless you hear obvious bad noises, I would be very reluctant to do major work on a good-running engine. Is 2 oz am hour really all that excessive? Is the oil leaking or getting past the oil seals on the valves (maybe easy to fix)? Unless you do lots of motoring, why not just live with it?

A modest increase in viscosity shouldn't hurt anything. If your engine fresh-water cooled it has a higher temp thermostat and may be very happy with a higher viscosity oil. The "CD" designation mentioned in earlier email is probably the SAE designation so "CE" or higher should be OK too. The "C" stands for "compression" ignition (i.e. Diesel) vs "S" for spark (gasoline). As each newer (better) SAE test is developed, the second letter increments (CE is newer better test than than CD). I think the latest level is CG/SJ. But don't use an oil with only an "S" designation because it is not tested for Diesel. Finally, switching oil types (eg natural to synthetic) can sometimes cause seals to leak, could that be your problem?

My 1-GM-10 (C), one-cylinder, 9 hp diesel engine on a 1982 CD 25D has recently started using oil excessively (1 1/2 qts. in 25 hours' running). I have checked with local diesel-service experts and also the Southeastern Yanmar distributor. They don't recommend use of any diesel oil or viscosity-enhancing addtives. Their only suggestion is the use of higher-viscosity oil than the SAE 30 recommended in the manufacturer's specs - SAE 40 or even 50 wt.
Anyone have any contrary or similar experiences or suggestions short of a ring job?

RitcheyVS@aol.com

[chuck yahrling]

you might want to check the oil pressure sender for a leaking seal.

My 1-GM-10 (C), one-cylinder, 9 hp diesel engine on a 1982 CD 25D has recently started using oil excessively (1 1/2 qts. in 25 hours' running). I have checked with local diesel-service experts and also the Southeastern Yanmar distributor. They don't recommend use of any diesel oil or viscosity-enhancing addtives. Their only suggestion is the use of higher-viscosity oil than the SAE 30 recommended in the manufacturer's specs - SAE 40 or even 50 wt.
Anyone have any contrary or similar experiences or suggestions short of a ring job?

Some ancillary info. A mechanic pointed out to me a rule of thumb for choosing oil grades: when switching from straight weight to multivis add 10 to the top grade to keep the same general operating viscosity. So, when going from 30W, use 15W-40 in multivis. Maybe you could try 15W-50. I mention this because I started using Shell Rotella (avail at Wal-Mart) for my 2GM13. I was using Pennzoil 30W but since Rotella is specifically mentioned in the Yanmar manual I got with the boat, I now use 15W-40 Rotella.

Also, there's great variation in filter qualities. For a few bucks more than a Fram you can get a Bosch that will work a lot better at keeping the oil clean.



cyahrlin@cisco.com