Yanmar 2GMF Questions

[john-o]

I'm servicing an old (new to me) Yanmar 2GMF. I want to remove and clean the heat exchanger but I can't find the drain port for the engine coolant. I have the original owner's manual and a shop manual but neither tells where the mystery drain plug is hidden. Perhaps the problem is that the engine is in a very confined space, with only about 3 inches clearance on each side, so I can only see the sides using a mirror and light, and then not very well. Anyway, if someone can tell me where it is I will be suitably embarrassed when it turns out that it's so obvious.

I'm also wondering if there's any reason I shouldn't have a machinist fit an oil drain plug into the oil pan. Again, because of the tight fit of the engine box it's very difficult to pull the old oil out of the very small (about 3/8 inch) dipstick hole. A drain plug would also allow removal of all the crud that sank to the bottom over the last 30-odd years. Is there a good engineering reason that caused Yanmar to so assiduously avoid oil drain plugs?

[four winds]

Should be on the underside (bottom) of the heat exchanger. Near the flywheel end on some models and farther forward on others.

The block drain is near the oil filter on the side of the block if you want to get it all out for a complete change.

[four winds]

In this pic...

A- drains the seawater from the tube bundle

B- drains the freshwater from the exchanger housing.

Note, this is from a manual covering all GM engines. Some illustrations are representative of the type and may not be the specific model of inquiry. But it's under there somewhere.

[Gary Mc]

I have a 2GMF and those pictures look about right.

[captstu]

I thought the Coast Guard prohibited a drain plug in the oil pan???

[Sailmonkey]

Originally Posted by captstu

I thought the Coast Guard prohibited a drain plug in the oil pan???

What? Care to cite this hearsay.

[Cheechako]

Unless you have an unusual situation there is usually no room for an oil drain pan under the engine anyway, thus a pug is useless unless you are going to drain to the bilge. Are you using a vacuum type dipstik oil extraction device?

[john-o]

Thanks for your help everyone, I found the coolant drain right where you said it was. As to the oil drain, there is lots of room under the engine to put a pan or even a funnel and jug to catch the oil (full keel), but I can barely get my hand near the dipstick. I'm an using a vacuum type oil extractor but it's very difficult and it must leave some residue.

[Stu Jackson]

Originally Posted by john-o

>>>>>>>>>>>>>>>>As to the oil drain, there is lots of room under the engine to put a pan or even a funnel and jug to catch the oil (full keel), >>>>>>>>>>>>>>>>>

You may want to consider adding an oil drain hose to the drain pan.

[four winds]

That's unusually good access to the pan.

Here's a no weld plug kit you might consider.


https://www.amazon.com/80250-Automat..._1512174850716

It's for auto transmissions which almost never have a plug, but of course would work fine for the oil pan, too. B & M is a well regarded performance transmission company for decades now. Probably good part.