R-21EC Yanmar 3YM30 Oil Leak

[tystutin]

Greetings, shipmates. Tug Life is a 2009 R-21EC powered by the Yanmar 3YM30 with 340 hours. Upon completion of my shutdown procedures yesterday, I discovered an oil leak at the rear of the engine (where the flywheel housing meets the marine gear). Oil is visible in the flywheel vent holes, and is also seeping from the rubber flywheel cover cap on the stbd side of the flywheel housing.

Upon further investigation today, I discovered that oil is actively seeping/spraying from the flywheel housing vent holes at higher RPMs.

A video of the leak: http://youtu.be/NJL-nZjXTNE

Any advice on how to tackle this? I'm scared that the culprit is a rear oil seal requiring haul out to address.

Alternatively:

(1) could the crankcase pressure be too high? Is there a crankcase vent/breather tube that should be inspected/cleaned; or

(2) could the oil be compromised somehow that is affecting viscosity and contributing to the leak? I'm using Delo 15W-40. One month and 15 engine hours after the last oil change, the color on the dipstick appears lighter than I remember. It may just be my imagination, though.

Any thoughts/insight/guidance would be sincerely appreciated. I'm beside myself with worry.

Tyler

 

[Kenny Marrs]

Hello Tyler,

I haven't seen an oil leak like this before. I think the easiest thing would be to contact a local Yanmar dealer in your area. Here is a link so you can find the closest dealer to you. http://yanmar.com/dealer/

Thanks,
-Kenny

 

[SGIDAVE]

Hello Tyler,

WELCOME to Tugnuts!

This appears to be oil from the engine's crankcase, correct? I see that it is NEAR the transmission, but that is not the source of this oil apparently.

You say you changed the oil 15 hr ago...could the crankcase be OVERfilled? My shop manual is...at the shop so I can't refer to it at the moment.

How long have you owned this boat?

I'm curious too as to the source of this leak. Please post back to this thread with the findings.

/david

 

[tystutin]

Thanks for the replies, Kenny and David!

Correct, David-source appears to be engine oil. Oil level as per the dipstick is correct and not overfilled.

Have owned the boat for over a year. Leak is new.

Thanks for taking a look.

Tyler

 

[Kaisardog]

http://yanmarhelp.com is a free site where owners can email their questions.

boatdiesel.com is a for-pay site where a member can post a question and often get a real-time reply from a knowledgeable mechanic. at $50 a year it is one of the best bargains in a diesel owner's budget.