coolant leak in Yanmar 20GM...

[smosh]

good morning all! I have a coolant leak seemingly in the top left front corner of the engine. There are no obvious drips from a hose or clamp, but somehow it's collecting on the fuel filter housing and dripping down off the motor. There's also fluid collecting on the block. I just can't see any active drips, or feel any spray. Linking to a video I just made - hopefully someone can point me in the right direction so I don't find myself replacing random hoses, clamps, and seals! Thanks!

 

[Ralph Johnstone]

Please clarify the model of your engine :

It's 2GM _ _ _ . I suspect a 2GM20F but please confirm all digits and letters.

Also it would be helpful if you can supply one or two single shots of the engine, face on and face up showing the source of the leak. There are too many sideways and upside down shots to clearly see anything and I've sweated over my 2GM20F for 25 years and have a pretty good idea of who's who and what goes where.

 

[Ralph Johnstone]

Got to take a break from working beneath the cockpit here so I'll guesstimate your engine is a 2GM20F. Your ID plate looks similar to mine (which proves nothing) :

There are no obvious drips from a hose or clamp, but somehow it's collecting on the fuel filter housing and dripping down off the motor.

With that observation, look here for leaks. The leak is above the level of the seconday fuel filter. Do a TP test and allow the engine to run for a while and is hot :

If no show on a TP test, take the boat out under full load and get it hot ~180° and see if the TP shows yet.

Back to the sweat hole .