260 Sundancer Oil Loss

[jpflhr]

I have a 2004 260 Sundancer with 350 mag with low hours on it 32 after running around the lake a few times about 6 hrs of time.
Alarm went off and shut down right away and noticed Oil Presure around 10 lbs so checked oil in the motor and no oil on dipstick.
added 3 quarts and all good got oil pressure back to 50 pounds and motor ran good top speed 5k RPM 37 miles an hour. Then 6 hrs later again alarm goes off and check the oil again and no oil? 5 to 6 qts in 12 hour run time?
Were is the oil going??? not in the billage not in the water and no smoke from engine?
Pulled boat from water brought to the garage check compression compression was within 190 to 200 psi all cylinders plugs all look ok no oil fouled plugs.. Changed Oil and thermostat boat was running a little cold. Now going back in the water and will monitor closely

Any and all comments welcome
Thank You
John

 

[Bt Doctur]

What Wt oil?

 

[LG111]

Check your oil cooler. If it failed it's going out your raw water exhaust. Pull and pressure test. Cheap fix.

 

[jpflhr]

What Wt oil?

Using 25/40 Mercruiser reg oil

 

[jpflhr]

Thanks for the info and will check this , so when you say going out raw water exhaust do you mean out of back of boat when engine is running?
If so.... there is no oil in water to see... or any sign of smoke if it was burning it.
This is totally baffling to me as the oil must be going somewhere???

 

[jpflhr]

Here is a pic of the plugs - 6 and 8 have some build up and not as clean as others but do not think I am burning this much oil with the way these look?

View attachment 47384

 

[CliffA]

are you sure the oil did not leak down into the bilge sump and get pumped overboard? it would only take a few seconds to pump it out and if you were not looking at the water at that time you may have missed it....only two ways to loose oil from an engine....leak it or burn it...

cliff