98 370AC Engine Alarm

[Rich S]

I have had a 98 370AC with 7.1L Merc's for 3 months. It has been a fresh water boat with good mechanical survey in Feb 07. I have put 30 hours on it with no problems (350 total hours). We just took it on a 5 hour cruise up the Sacramento Delta and after 3 1/2 hours of cruising at 9-10 kts the starboard engine alarm came on. Water temp. and OP were good, everyting seemed fine, however I had our inflatible dinghy on the extended swim platform and it had filled with quite a bit of water adding a lot of weight. :smt021
I removed the dinghy and all seemed well...no problems with the alarm. I think the added weight caused a back pressure in the exhaust as the alarm stopped once the dinghy was removed. My question, Could this cause the alarm?

I thought everything was fine, until our return trip...towing the dinghy. Now the bilge alarm went on, upon inspection there was a couple of inches of water in the well between both engines. Everything around the engines, sea cocks, sea strainers, hoses, manifolds, etc. were dry even with engines running. There are two Rule 2000 pumps however one pump did not seem to be working, I moved the float and could not get one to activate. This seems like a dumb question, however can pumps fail and allow water back into the boat? FYI, I cleaned the water and we had no other problems for the last hour, the bilge was dry once back at the slip. This casued more confusion as I do not know where the water came from.

Thank you in advance for helping with these "silly" questions.
Thanks,
Rich S.

 

[fwebster]

The water in the bilge could have come from anywhere.....a leaking cooling hose, a leaking freshwater fitting, rain, a/c condensate draining into the bilge, a deck hatch gutter stopped up, etc.

My guess is the alarm you heard was the high water alarm which comes on when the emergency bilge pump activates.

Bilge pumps do fail, but very infrequently. You probably have a corroded or broken connection on the float switch for the pump. Cut off the cable ties and separate the wiring and you may see a beak or loose wire. If not, then cut the float switch butt connectors out, stip bac the insulation until you get to clean wire. Next, Temporarily connect the float switch to verify that it and the pump do work. If so, splice in new butt connectors......use only silicone filled heat shrink connectors since this is a very wet enviornment.

To find a leak in the bilge, I usually vacuum/pump all the water out and let thebilge area completely dry. Then start up various systems one at a time and look for water leaks. If you have sharp eyes, you may see a drip. If not look for an accumulation and follow it up hill.

Hope thiat helps...........