Pinging "Tree" - Yanmar Oil Plug Leak Due To Rust

[Paddy]

I believe a few years back when you first took delivery of your Albin you discovered an oil leak coming from a rusted out block plug behind the raw water pump on the Yanmar 6LP. I also recall it being quite a project to repair.

I now have the dreaded oil leak that appears to be coming out of a block plug (looks like a freeze plug). Hopefully you, or if I am mistaken, the person who did go through this ordeal can give some advice.

Looking to know if the injector pump is a simple bolt off and back on but my fear is that it is not.

Might be able to get to the plug by just removing the raw water pump, but will be 100% easier without the injector pump.

Also, did you replace the plug with Yanmar replacement or custom fabricated?

Thanks in advance.

Rob

[Tree]

Hi Rob,

Sadly not - the only way to properly fix it was remove the engine in order to remove the fuel pump as access to pulling off the drive gear is not possible with the bulkhead being so close. I pulled it and while the engine was out needle gunned the engine back to bare metal, primed and repainted with two part pack. To this day the engine is still rust free.

With regards to the seal, i didn't ever want it happening again so tapped and fitted a 3/4 UNF bolt with a dowty seal underneath - you can replace the core plug with a stainless one but my way of thinking was i didn't want to fit it all back together only to find I hadn't seated the plug perfectly only for it to leak again! The core plug is 16mm for reference and isn't a Yanmar part as this is fitted during the block manufacture at Toyota, it is also the only core plug on the engine that is steel.

You could temporary fix it by screwing in a self tapping screw, or plug with an epoxy metal. I chose not to go that route as many of my trips I can be running for up to 10 hours and didn't want to risk it.

[Tree]

viewtopic.php?f=7&t=6995

[Paddy]

Thanks, i may have to try the temp route for now. Not starting the season off on the right foot!

[Paddy]

Are there any other plugs I should be concerned with?

[Tree]

Not on the oil gallery. It's one that is there for machining purposes only. It's not there to act as a freeze plug etc. All the other plugs are stainless steel fitted by yanmar and they're on the water side.

[Paddy]

Thanks Tree, last question...

Based on your experience, can a good diesel shop tap and/or plug the hole without pulling the engine?

[Tree]

They maybe able to but I wouldn't bank on it. My mechanic is the bees knees and he had three or four attempts and just couldn't get the angle on the damn thing. It's worth a shot to try that route first but if it fails there is no going back, you will have to pull the engine to make it good and wouldn't be able to do a temporary fix. I'd get some advice first from someone you trust there. If you do choose the temporary fix, I recommend devcon as a putty to make good for the season, just be sure that surfaces are spotless clean before applying.

[Paddy]

Just met with my local guy who is one of best diesel mechanics in the area, he said he done one already and knows of the problem but agrees with you that he can't guarantee that the engine won't need to be lifted to do it properly. Coming this Friday to take a better look. The good news is that his shop is 1000 yards away from me.

Will keep you all posted.

[Paddy]

Somehow we appear to have plenty of room, the mechanic didn't even take the cover off. Injector pump is being sent out for bench testing per the mechanic's suggestion and he is working on plugging up the hole.

So far, so good, will get some pics.

[Tree]

Excellent news!

[Paddy]

Some updated pics for you all that I also posted on Boat Diesel. The mechanic made some sort of custom puller for the pump gear and was able to get it off without pulling the engine or fuel tank.

Cleaning it up for me, hoping to have it back by this weekend.

[Tree]

I must admit Rob, you've got a lot more room behind the pump than I did. I have a full bulkhead right there. Probably why your mechanic had the room to pull it. Also cambelts will be much easier to change for you with that much access.

[Paddy]

Not sure if Albin decided to move the Yanmar engine forward during the later years or mine was just "dropped" with a bit more clearance. I do feel better knowing that I have plenty of access for future issues.

Definitely something I would look at as a prospective Albin buyer!

[roaringcreek86]

having same leak from plug tried 2x can't get plug to seat