[C320-list] Intermittent coolant leak

[Sara Skinner Schroeder]

Hi guys,

Over the past 8-9 months I have an intermittent coolant leak that I just can't find. Over the past 8-9 months it's leaked about 5 times.  I have a 2000 C320 (#707) with a Yanmar 3GM30F. She has about 1450 hours on her.   I have narrowed it down to the following:

1. It is coolant - not diesel (yes I've tasted it).  It leaks about the equivalent of a tablespoon+.

2. It leaks on the starboard side of the engine compartment about halfway between the front of the engine compartment and the back of the compartment (right where the bulkhead is and right around the fuel pump/fuel filter). It never leaks on the port side.

3. It only leaks when I am on a port tack and am leaning over pretty hard.  Never leaks if I am not heeling over hard.  The fluid will pool on the starboard side of the galley floor and then drip over to the port side when I change tacks. 

4. The leak seems to "spray" all over the inside of the engine compartment which suggests the engine needs to be under load - but when I turn on the engine and put her on a lean but I can't see where it's leaking. 

5. I wipe down the inside of the compartment each time it happens so I can see where the new leak appears.  The pattern is always the same.

6. I replaced the radiator cap thinking it was leaking from the top of the radiator but it still leaked yesterday with the new cap on (yes, it was on right).

7. It is not coming from the overflow tank as it's always dry and there are no leak marks on the side of the container.

8. I have absorbent pads on the bottom of the engine bag but there never is a pink stain on the pad. The bay is dry.   

8. I have spent hours with a little expandable mirror looking for a cracked hose, loose nut, anything. Nada.  Have also run my fingers over the entire starboard side trying to find a leak but I can only do that once the engine has cooled down and by then the fluid is drying up.   


Am beyond frustrated so am reaching out to this wonderful community.  Any ideas would be appreciated!  Note: I do not posses the 'guy gene' that makes diesel engines understandable.  Am slowing learning how to do my own maintenance but need pretty specific directions! 


Sara

Wandering Star/Seattle