View Full Version : MG30 Yanmar Oil leak

12-15-2005, 02:02 PM
MG30 Yanmar - Oil leak from large gasket timeing cover. Gasket actually escaping. Can I push in and apply some kind of sealant to stop leak?


12-20-2005, 03:52 PM
no it wiil not work. you must install new gskt.

12-28-2005, 01:04 PM
"I think you have a 3GM30 F stands for factory fresh water cooling. Looking at the t/c the leak is about 5 o'clock in the oil filter area.
ORDER IN THE 121575-01512 gskt. They may want to sell you the -01511 gasket, but the -01512 hangs in better. It is used on the industrial version and has a graphite composition. Do not forget to change the 2 o-rings that go onto oil ports between cover & block & gasket. p/n 24311-000100"

poker casino143
03-06-2006, 09:56 PM
"***** ****** ***** 499 ("")"

Ed Donahue
06-21-2008, 08:49 PM
Have a 6LP with 170 hours. On a test run the mechanic pushed the throttle clear forward and the engine bogged down and so much smoke came out the Coast Guard thought the boat had a fire onboard ( no kidding ). It works fine with a slow increase in speed and at high rpm.
Is this a sign of potential serious problems? It should be noted that the service center overfilled the oil, I put about 9 hours on it and they pumped out the oil to operating level. THKS, Ed"

Ed Donahue
06-21-2008, 08:53 PM
"On the Yanmar of interest to the Coast Guard, I should have mentioned the oil over fill was 9 hours before being pumped down to normal level. The problem occurred with high oil and normal level."

06-21-2008, 10:59 PM
"Hi Ed, keep an eye on it. Overfilling these engine with lube oil is not a good thing.
Call your local Authorized Yanmar Dealer or Yanmar direct and get their feelings on this, How much was it overfilled?"

Ed Donahue
06-23-2008, 12:09 AM
"Hi Ron,

About 3 quarts. Experienced Yanmar mechanic to advise tomorrow, Will post the reply."

Ed Doanhue
06-24-2008, 08:09 PM

Factory rep from Georgia, said no problems, just run it normally and at high rpm if idling for a long time. Also, oil will spill from the vent if boat is at an angle during a initial full throttle push before plane angle.
Still waiting for more input.


06-24-2008, 08:27 PM
Your engine is a turbo changed unit. Avoid low RPM and Idles. Run at the cruising range and change lube oil on schedule. Also have the valve lash adjusted once a season. I am glad you went to the horses mouth for their professional advise. Overfilling with lube oil creats foaming and can also bend con rods.

Pat MacDonald
08-19-2008, 09:28 AM
"Yanmar 3gm30f (2000 -360hrs) Engine question/problem?
After running the engine under a load for awhile (anywhere from 45 -120 minutes averaging 2500rpms as well as idling out of gear at 1300 for about 30-60 min to charge batteries) and then sailing for up to 4 hrs, when I try to go back to the engine power, both the temp and the oil light come on, the alarm beeps and the engine does not start. After approx 5 min of trying to start it it finally turns over and the lights and alarms go off immediately and I have no problems once running
When I start it at the beginning of the day, only the oil light comes on, the alarm beeps and it starts right up. To start this engine I open seacock, check all fluids, turn battery dial to both, put key in, go to 1/2 throttle(out of gear) turn key to on and push the button"