Coolant leak

[Nom De Guerre]

Please review these pictures and let me know your thoughts. This is what I found after checking in on the boat after our latest cold snap. Green antifreeze from the closed side of the system (open side winterized with pink PG), underneath the engine.

I was able to trace drips from there up to two oil pan bolts, and from there up to underneath one corner of the alternator. From there, the investigative trail runs cold (last picture is the engine top, no evidence of a leak seen in and amongst the piping up there).

What's next, pull the alt and look for the source above it?

















It's a yanmar 2gm in my h28.5.

 

[Stu Jackson]

1. Painted hoses often indicate old hoses (unless your engine is brand new).

2. Connections are often the cause of leaks, even if they "look" OK; check all the hose clamps and the condition of the ends of the hoses.

3. Just 'cuz you can't see anything up higher doesn't mean it didn't happen. Sometimes the start line of the drip dries out first, and that's wy your paper towels caught the drip at the bottom.

4. I once had a leak, had trouble tracking it down, found that my HX bracket, hidden underneath, had sheared and rubbed the shell of the HX to a point where it dripped.

Good luck.

 

[Ralph Johnstone]

Here's another pain in the arse you may want to check on ...............

http://forums.sbo.sailboatowners.com/showthread.php?p=1082768&highlight=antifreeze

 

[Rich Stidger]

I feel your pain. My engine, a Volvo MD22L-B, although quite different from yours, also has a persistent green antifreeze leak- but only over the winter. This problem is at least 10 years old. Like you I have traced the leak up to a point, and in my case it may originate behind a motor mount, and possibly at a freeze plug. I have checked, tightened, and finally replaced all of the hoses in the area with no joy.

Over the winter my overflow tank becomes empty but the source of the leak is well below the tank. My tank is bulkhead mounted and no wetness or leaks directly from the tank can be found. It looks like I have an engine leak and the overflow tank simply makes up for the leak until it is empty.

Refilling the tank in the spring and running the engine does not seem to pull in any significant amount of antifreeze to replenish a partly empty engine. It seems like just the amount in the overflow tank leaks and then stops.

The last couple of years I have drained the overflow tank at the winter layup. The leaks stopped. So I have given up trying to find the leak and I simply drain the tank in the fall and refill it in the spring.

There are no leaks during the sailing season. If I had a leaking freeze plug or hose, I would expect it to seep or drip at least a little over the season. But nothing, bone dry.

 

[kloudie1]

On the 2 GMF, there is a "freeze plug" and a pipe plug behind the alternator, on the engine block.. The water pump lower port side hose is also there..Three possibles. Probably time to pull the alternator for a look-see

 

[Nom De Guerre]

These are some great tips and bits of advice. I'll poke around some more after it warms up again, and report back here.

Thanks to all.

 

[Warren Milberg]

Reach your hand back and over the top of your engine. Feel around the exhaust elbow and back behind the heat exchanger .I think you'll find the leak in that area.

Depending on your physical size (smile), you can also squeeze your upper body over the engine and actually look at these areas, or use a small mirror and flashlight. This is not for the claustrophobic.....

 

[Nom De Guerre]

Thanks Warren, I'll check that area over too. I'll likely have to resort to the mirror/light or phone cam trick, at 6'2", 190 lbs.

Or maybe it's time to cut in a rear maintenance hatch...

 

[petersea]

"cold coolant leaks" are more common in larger diesel engines but can happen in smaller engines , brought on by colder temp and metal contracting and expanding. Often just doubling up the hose clamps will fix it. Based on your pictures I would put all new hose and clamps on anyway. You can always try a pressure test on the system and that should expose the leak. Good Luck