Closed cooling system, water in bilge.

[whiskeyRichard]

I recently purchased this boat and as is normal, it is going to put me through the paces with repairs.

It is a 1980 Mercruiser 260 I/O with a closed cooling system. The boat and engine have been well maintained.

After a few hours on the lake, there was A LOT of water in the bilge....hot water. It drained out the drain plug so I can only estimate, but I figure there was 20-30 gallons.....and apparently the bilge pump is not working either.

I am trying to figure out where the water is coming from. There is a little evidence of leakage around a couple fittings on the tube with the 90 brass fittings in the pictures, but certainly not enough to let that kind of water in. I have run it in the driveway for about 30 minutes with the motor in tank of water and never saw a drop.

I have checked the hull and there is no damage there that would allow water into the bilge.

I am guessing that I need to get around the rear of the motor and look around there while in the lake and running, but I figured I'd check here for some advice before I head out.

I have attached some pictures.

Thanks for any help,
wR

 

[TyeeMan]

Either tied up to the dock or on the muffs at home, fire it up and start looking around. Check the hose clamps on any rubber components on the exhaust system, if a hose clamp is loose on those items they will leak hot water. Check where the exhaust Y type connects to the boat way down low on the transom, see if water is leaking out there.

But, best bet is to fire up the engine and start looking. Being it's hot water you shouldn't have to look too far.

 

[Bt Doctur]

Warm indicates leakage from the raw water side of the heat exchanger . May be the Y pipe leaking. But that would leak water into the boat with the motor off. Heat exchanger end caps, gaskets?

 

[whiskeyRichard]

I've run it twice on the muffs in the driveway for about 30 minutes each and didn't get a drop of water in the bilge but I did make a holy mess of the driveway......gonna need to work on that drainage before winter I guess.

Thanks for the help,
wR