Yanmar 3GM oil line failure

jrd22 · #1 (**permalink**) 11-25-2011

My brother and I installed a new 3GM in the early 90's and apart from normal maintenance it's been trouble free and still looks almost new. A few weeks ago it was run while in the slip for about 20 minutes. I checked the oil prior to starting it a week later and there wasn't any oil on the stick. There was a lot of oil in the bilge and after filling the engine up to the full mark on the stick I started it up to find the leak. I had noticed some oil near the back of the engine on the starboard side prior to starting it and sure enough there was a large stream of oil running down the block there. It was coming from a very small oil line that goes from the starboard side of the block by the injection pump around the back of the engine and then down around the port side under the starter. There are a total of four banjo fittings in this little line and it must have developed a crack for some reason and let go. This is a steel line by the way and there was a little corrosion near the leak so it probably wouldn't have been long before it rusted through and started leaking there (not an easy place to see). The new line looks to be copper so corrosion shouldn't be a problem. Installation wasn't too bad but did require two people to get the copper washers behind the banjo fittings. I didn't even realize there was an external pressure line on the engine. Anyway, just a heads up if you have an older 3GM, it could have destroyed the engine if it had been running at high RPM. The low oil pressure alarm never went off and appears to be working properly, although I would have thought it would go off if the engine was three quarts low (which it was).

casey1999 · #2 (**permalink**) 11-28-2011

Thanks for the heads up. Also have a 3gmd that has quite a bit of corrsion. Plan to clean and paint the engine in next few months, may end up replacing some of the oil lines as you suggest.
Regards

ggray · #3 (**permalink**) 11-28-2011

BTDT
Mine pumped out all the oil until the alarm went off. Shut it off immediately. Real mess, but no damage to engine.
You might be right, but I suspect it is just a copper coating of some sort.

jurgenvoigt · #4 (**permalink**) 01-02-2012

My 2001 3GM30 has also developed an Oil Line Pin Hole,... took me weeks to find where the oil was going... Until I source a replacement, do you think I could use epoxy putty or tape until it arrives,...

I'm currently out in the Pacific on the yacht and not close to port for weeks..

Did you find an after-market replacement ??? like those flexible Braided type,.. Where & What Price ??

What price are the Yanmar replacements .. Where from..??

Ordering online would be good for me...

I have a number of other parts to order..

Thanks for your help
Best Regards

Jurgen
In the Pacific..

smurphny · #5 (**permalink**) 01-02-2012

Thanks for the heads-up. I'll have to check mine.

Rockter · #6 (**permalink**) 01-03-2012

Yea, there is a similar line on the Volvo MD17C that runs from the oil filter region, over the top of the motor to the injection pump region.
Twice it has blown the banjo off and pumped the motor dry.
What on earth is it for?
Is there much flow through it?
Can I use a braided line instead?

casey1999 · #7 (**permalink**) 01-03-2012

Quote:

Originally Posted by jurgenvoigt

My 2001 3GM30 has also developed an Oil Line Pin Hole,... took me weeks to find where the oil was going... Until I source a replacement, do you think I could use epoxy putty or tape until it arrives,...

I'm currently out in the Pacific on the yacht and not close to port for weeks..

Did you find an after-market replacement ??? like those flexible Braided type,.. Where & What Price ??

What price are the Yanmar replacements .. Where from..??

Ordering online would be good for me...

I have a number of other parts to order..

Thanks for your help
Best Regards

Jurgen
In the Pacific..

Try this Yanmar Rep:
Torresen Marine - The Sailboat Specialist
The should be able to help. They have and email on the contact information.
For short term maybe wrap the leak with some tape (duct) and then put a hose clamp over the tape and tighten. Might leak a small amount but may slow down the larger leak. Just epoxy on a small line may not hold. Maybe epoxy, tape then a hose clamp.
Regards

jrd22 · #8 (**permalink**) 01-03-2012

Quote:

Originally Posted by jurgenvoigt

My 2001 3GM30 has also developed an Oil Line Pin Hole,... took me weeks to find where the oil was going... Until I source a replacement, do you think I could use epoxy putty or tape until it arrives,...

I'm currently out in the Pacific on the yacht and not close to port for weeks..

Did you find an after-market replacement ??? like those flexible Braided type,.. Where & What Price ??

What price are the Yanmar replacements .. Where from..??

Ordering online would be good for me...

I have a number of other parts to order..

Thanks for your help
Best Regards

Jurgen
In the Pacific..

Hi Jurgen, Rather than epoxy or tape I think I would use a thin piece of neoprene if you have it rolled around the tube with a hose clamp right over the pinhole leak. This would only work if the leak is on one of the straight sections of the tube (our leak was at a bend).
My brother didn't look for an aftermarket replacement, I think it would be unusual if one was available. It's a very unusual tube with four banjo fittings and everything has to line up perfectly in order to fit. I think it was less than $100 US (ridiculously high for what it is), but I don't have an exact cost. You will need eight (get ten or twelve, they are easy to lose in the bilge) copper crush washers as well.
Good luck.

ggray · #9 (**permalink**) 01-04-2012

I may be dreaming, but I think I was pleasantly surprised at the price. Of course, it was not an item normally stocked even by a major source.

S34 · #10 (**permalink**) 01-13-2012

Torresons won't ship to anywhere other than their dealership area for Yanmar parts.
That is either Cu coating or yellow electro-zinc because its steel underneath on the OEM lines. I coated mine with flexible epoxy when I replaced it. $47.50 + $6 for Cu washers. You won't need the banjo bolts as you can use the old ones.

As a temporary repair i would put a tiny bit of tape over the pin hole, then clean the line and wind some epoxy impregnated fine (4oz) cloth around it. or just epoxy with finely chopped glass mixed in and blobbed onto the area, building it up with multiple batches to withstand the pressure.
Depends where the pinhole is.