Huge oil leak on a 3GM30F

[Bluenose]

My wife and I had just motored and stopped at our mooring. I went below to shut off the cocks and the engine compartment was flooded with oil and there was nothing in the crankcase. There was no low oil pressure buzzer.

I did a search, and apparently this is an issue with these, something to to with an oil line.

Anyone have any suggestions, other than suggesting I take up golf?

 

[Calif. Ted]

Starboard side of engine there is a steel (painted) oil line runs from the front of the block under heat ex near injector pump to rear of the block. The most common problem area is towards the rear where water leaks make it prone to corrosion.
See Fig. 31 labeled Lub. Oil Line in the engine manual on the link attached.
https://j109.org/docs/Yanmar-3GM30-parts-catalog.pdf

 

[Don S/V ILLusion]

Golf is fun. Clubs cost much less than a jib and there's no maintenance required. Hope this doesn't sound condescending but it's hard to examine your engine oil and filter lines from here but it's clearly that would be the first step. As it sounds like you blew all the oil out, the high pressure lines seem a likely suspect.
If it's any consolation,consider yourself lucky you didn't cease the engine. The fix is probably much easier than the cleanup will be.

 

[Tally Ho]

My wife and I had just motored and stopped at our mooring. I went below to shut off the cocks and the engine compartment was flooded with oil and there was nothing in the crankcase. There was no low oil pressure buzzer.

I did a search, and apparently this is an issue with these, something to to with an oil line.

Anyone have any suggestions, other than suggesting I take up golf?

I’ll trade you my clubs for the Bene, and I will even clean up the mess!
Clubs have very low miles on them, used once a year these days (literally)....

Sounds like you are lucky your engine didn’t seize up.

Greg

 

[LeslieTroyer]

I’m still cleaning up oil from whe the P.O. broke the timing cover of my M25 and blew a hole in the oil filter. That was about 5 years ago.

Les

 

[kloudie1]

If the alarm didn't go off, ya probably OK on the engine.. find the leak and fix it.. If it is the oil pipe, the part is about $50 (US) .. The pipe starts at a "banjo" fitting on the lower port side, goes aft and splits into two.. one up to the head and one goes around to starboard to feed the camshaft.. then add oil and crank up.. .. Good Luck

 

[Bluenose]

Thank you all, this seems to be an issue with these engines.

 

[kloudie1]

A good automobile "brake shop" could fix the pie.. The pipes are silver soldered into the banjo fittings.. they could replace all the tubing if you have a problem finding a new part..

 

[nfg2u]

I had the same issue with my 3GM30F. Here is the new line from Yanmar. Took about 3 hours to replace. I had to pull the starter, after that it was pretty straight forward. I think it was around $80.00.

 

[Bluenose]

OK, I finally got to the bottom of it when the tech looked at it. It was a pinhole leak, and not a catastrophic loss. When he put one quart of oil into it was almost full. So thankfully not the problem I thought it was. I still can use it and he will install a new oil line when it comes in.

 

[Jimmymak]

Just replaced my oil line as well and the advice here was great! Removed the starter motor and loosened the secondary fuel filter bracket bolts. This allowed me to get better access with a ring spanner on the bolt which sits directly behind the secondary fuel filter housing. Topped her up with oil, cranked her over and no leaks!! Happy camper

 

[Bluenose]

I also need a fuel line replaced in the same area as the oil line. The tech said it looked like water had somehow got on that part of the engine and rusted both. Not sure how that could have happened, as above this part of the engine there are no access points, the binnacle being well aft.

Any thoughts??

 

[kloudie1]

Water may be from heat exchanger directly above . Sea water leak from end caps drooling back under maybe?

 

[Claude L.-Auger]

Glad you got the oil problem fixed but I'm left with a question ? Quoting from your first post :"the engine compartment was flooded with oil and there was nothing in the crankcase" and from your 3rd one: "he put one quart of oil into it was almost full". I understand a few ounces of black oil splashed into the engine bay may look like a flood, but a 3-cylinder Yanmar crankcase capacity is 2.6 liters (almost 2.75 qts). Effective capacity is about 1.6 liters. Did you check oil with the dipstick and didn't see any on it hence the assumption no oil left ? That would explain adding one quart and being almost full. That would also explain the no buzzer, because the oil left in the engine gave it oil pressure...and prevented the engine from ceasing. As to rust marks and water, I have the same question as Kloudie, but also have seen condensation caused by high humidity do it over time. Put diaper pads under the engine and top up your oil level until the line is replaced. Good luck

 

[Bluenose]

"Did you check oil with the dipstick and didn't see any on it hence the assumption no oil left ? That would explain adding one quart and being almost full. That would also explain the no buzzer, because the oil left in the engine gave it oil pressure"

That's exactly what I did. I was in a state of shock! I thought that all the oil went at once and it did not. He confirmed what you said - lots left, thankfully. Thanks for mentioning the water from the heat exchanger - I will mention when he comes back for the fuel line.

 

[Charles Erwin]

I think the new ones are copper nickel alloy and if so rust is not a problem any longer.

I still paint them though. Also they can chafe where they pass under the starter motor so maybe a piece of split poly tube for cushion there. Trivial pesky details these but maybe worth it.

Charles

 

[Bluenose]

Thank you. Never had this happen before with three prior Yanmars. Tech suggested I spray with WD40. Although I have taken a number of diesel courses, never knew they had an external oil line - until now!

 

[Jimmymak]

I’m about to replace the fuel line to pot 1 as the injector is corroded but moreover, the fitting is seized in the injector! ( see photo). I can’t bleed at the injector, so both the injector and the fuel line need to be replaced. The other 2 are fine so my guess is a leak in or around the injector??

 

[jssailem]

@Jimmymak Looks like you tried to remove the fuel line nut and the wrench slipped.

It is time for a penetrating oil. Squirt on the injector side back against the nut. Tap the nut to help the oil to penetrate along the threads.

Also use a fuel line wrench.
Something like this is less likely to slip.

 

[Jimmymak]

Yes I agree. I’ve used the “flared” spanner as well but to no avail . The nut was rounded off by previous owner/s and penetrol/multi grips didn’t work either. I’ve purchased the new parts now so I’m committed to replacing the injector and fuel line but the leak and corrosion is still a bit of a mystery. I will just have to keep an eye on it!