Sudden oil loss-Yanmar

[wingssail]

We are in a remote area of Costa Rica and we have some serious problem with our engine.

Yesterday the engine alarm sounded (started chirping) and we saw low oil pressure and shut down the engine. The oil level did not show on the dipstick.

We put in two quarts which brought it up to nearly full and restarted the engine. Within 1 1/2 hours the oil was gone and the pressure low again.

We found no oil in the bilge, no smoke, no strange sounds, nothing obvious about the looks of the exhaust or raw cooling water being exitited.

Today, suspecting the oil cooler, we bypassed that (rerouted the water hoses) and after refilling the oil, started the engine. No oil is leaking out the oil cooler water passage, none. We again checked the bilge, no oil, the blowby hose to the aircleaner, no oil, and no smoke or oil is visible in the exhaust, however a slight sheen (rainbow) is visible in the exhaust water spray.

Later we will go ashore an try to find some more oil to buy and then begin to work our way to Punta Arenas where maybe we can get some mechanical help. It will be slow since the wind is light in the afternoons, and zero during the rest of the day. We are somewhat depressed. Without the engine it will be a long trip. plus we can't charge the batteries sufficently with just solar. We may have to shut down the refer.

Any ideas about where his oil is going?

Fred Roswold, SV Wings, Costa Rica

[Cheechako]

What yanmar? Is starting a bit harder than usual?

[model 10]

Is it a turbo?

[Cavalier]

Originally Posted by wingssail

We are in a remote area of Costa Rica and we have some serious problem with our engine.

Yesterday the engine alarm sounded (started chirping) and we saw low oil pressure and shut down the engine. The oil level did not show on the dipstick.

We put in two quarts which brought it up to nearly full and restarted the engine. Within 1 1/2 hours the oil was gone and the pressure low again.

We found no oil in the bilge, no smoke, no strange sounds, nothing obvious about the looks of the exhaust or raw cooling water being exitited.

Today, suspecting the oil cooler, we bypassed that (rerouted the water hoses) and after refilling the oil, started the engine. No oil is leaking out the oil cooler water passage, none. We again checked the bilge, no oil, the blowby hose to the aircleaner, no oil, and no smoke or oil is visible in the exhaust, however a slight sheen (rainbow) is visible in the exhaust water spray.

Later we will go ashore an try to find some more oil to buy and then begin to work our way to Punta Arenas where maybe we can get some mechanical help. It will be slow since the wind is light in the afternoons, and zero during the rest of the day. We are somewhat depressed. Without the engine it will be a long trip. plus we can't charge the batteries sufficently with just solar. We may have to shut down the refer.

Any ideas about where his oil is going?

Fred Roswold, SV Wings, Costa Rica

If you're certain it's not making its way into the cylinders (being burned) or into the coolant system or the bilge - then it must still be in the engine. Does your Yanmar have the optional turbo? as there is an additional intercooler loop to check.
If your exhaust is standard then you could consider catching some of the exhaust water in a bucket to see if there is any oil content.

That's a lot of oil to go missing.

If it's still in the engine, then there's a chance that the oil is not filtering back down into the sump (due to blockage) properly, and is being trapped higher in the engine. Before putting any more oil in, try leaving in for a day or two to see if there is any increase in the oil-level in the sump. If it's possible that the oil is still in there, you don't want to run the risk of overfilling until you're sure where it's actually going.

[sailorchic34]

That sheen on the water tells you its coming from the engine or oil cooler. 2 quarts in 1.5 hours is massive. I had three broken rings on one piston and only used 1 quart every 12 hours or so. plus it was hard starting hot or cold.

I'm thinking head gasket or oil cooler. As the oil cooler is not leaking then it could be the head gasket. Or its the infamous yanmar broken rings which is not at all as uncommon as it should be. With luck you have or can find a head gasket. Easy fix if that's what it is. Hows the coolant water looking?

Not much else it can be, unless its a turbo.

EDIT: Oh easy test, pull the oil fill cap off with the engine running at idle. See lots of smoke come up out of the opening.... It's rings.

[a64pilot]

My bet is head gasket. That much oil and you would see smoke if it were turbo I think

[Cavalier]

Originally Posted by sailorchic34

That sheen on the water tells you its coming from the engine or oil cooler. 2 quarts in 1.5 hours is massive. I had three broken rings on one piston and only used 1 quart every 12 hours or so. plus it was hard starting hot or cold.

I'm thinking head gasket or oil cooler. As the oil cooler is not leaking then it could be the head gasket. Or its the infamous yanmar broken rings which is not at all as uncommon as it should be. With luck you have or can find a head gasket. Easy fix if that's what it is. Hows the coolant water looking?

Not much else it can be, unless its a turbo.

EDIT: Oh easy test, pull the oil fill cap off with the engine running at idle. See lots of smoke come up out of the opening.... It's rings.

+1 it does sound a lot like a c.h.gasket issue!

[Cheechako]

If a head gasket it either is going in the coolant (easily checked) or smoking out the exhaust right? (easily checked)

[sailorchic34]

Originally Posted by Cheechako

If a head gasket it either is going in the coolant (easily checked) or smoking out the exhaust right? (easily checked)

True, But your not going to loose a quart of oil an hour to the coolant. Either its in the bilge, out the water side of the oil cooler (assuming raw water cooled), or entering a cylinder via a blown head gasket, or from trashed/ broken rings and being burned. Or if a turbo, could be a blown seal in the turbo.

From personal experience with my broken rings, basically no rings, I was burning a quart every 12 hours. A far cry from 2 quarts in an hour. So I don't see that as high probability.

A cracked external oil line could easily leak 2 quarts in 1-1/2 hours. But the bilge would be black. Same with a cracked oil cooler except its going overboard, not all that uncommon with yanmar either. The oil sheen points to the oil going out the exhaust.

We need to hear back from the OP as to engine type.

[wingssail]

Originally Posted by Cheechako

What yanmar? Is starting a bit harder than usual?

The engine is a 3JH2E, non turbo. 5400 hours. Never been hot or had any other significant problem.

It is not hard starting, it always starts instantly upon cranking.

Further, I have, one by one, cracked open the injector nuts and noticed that each one causes a similar drop in engine RPM, implying that all cylinders are contributing equally.

My current thinking is that I have a worn or broken valve stem seal on an exhaust valve which permits lube oil to seep into the exhaust port and get blown out with the raw water coolant. I collected pail of coolant from the exhaust and found oil sheen on it.

I've just bought 4 gallons of lube oil and I will sail/motor to the nearest town to try to find a mechanic.

[wingssail]

Originally Posted by sailorchic34

Oh easy test, pull the oil fill cap off with the engine running at idle. See lots of smoke come up out of the opening.... It's rings.

No smoke out the oil fill cap, no smoke or oil collecting out the breather hose (goes to air cleaner).

Definitely not much oil collecting in bilge, we put a foil pan there and during the period that we lost a quart (30+ minutes) got a couple of drips, which looked a lot like spillage from when we added oil.

I don't have tools (or skills) to do this type of engine work, my biggest concerns for when I get to Puntarenas and find a mechanic, are: can they get old engine bolts out, and how hard will it be to get parts.

One good thing, its easy to access, you can sit on either settee and the entire engine is exposed right at your knees.

Thanks for all the interest so far, folks. I was hoping for a miracle cure, looks like nothing but do it the hard way.

[model 10]

I can think of much worse places to be stuck than Puntarenas. I don't think you will have any trouble finding help. To bad it's so far up there.

[marlinmike]

Is this engine raw water cooled, or you have a heat exchanger? That's a LARGE amout to be using, if going out the exhaust you would have a nice slick forming. If burning in a cyclindar from say a head gasket it should be really smoking. Interesting problem for sure.

[Cheechako]

Yeah, it's a large amount. Exhaust should be smoking like a locomotive. Is there any way for the oil to be returning to the fuel tank via the return line? Something doesn't add up... it's gotta go somewhere....

[sailorchic34]

Well that all cylinders are working find is a very good sign.

Did you check that the crankcase breather was clear. That is take the hose of the valve cover and blow into it. IF clogged it could cause oil consumption.

check for oil in the coolant tank too.

Probably not an exhaust valve stem leaking as when the exhaust valve is open the cylinder side is pressurized from combustion. Oil normally only enters via the intake valve guides.

My primary guess is the oil cooler is leaking. It's the only thing that could leak that much oil in that short a time. Could be a head gasket too, but 2 quarts is a massive use rate. Valve stems would not use that much. That sheen of oil is unburnt oil. If the head gasket was blown then you would see blue grey smoke out the exhaust not oil sheen on the water.

When you tested the oil cooler before, was the engine cold or hot. I'm thinking when cold the oil cooler may be bypassed as the oil pretty much bypasses the oil filter till it's warm enough to flow through it anyway. Easy check is bypass the raw water around the cooler and run the engine for 15 minutes at low speed till it reaches operating temperature. I'm betting you'll see oil leaking out the water side.