Overheated engine

July 28, 2014  leaving Tahiti


Finally, finally we are heading back to Moorea.  Most of the projects are done, especially anything involving purchasing parts or downloading computer files.  It is a bright day with a brisk breeze.   Anchor up, we head out of the mooring field and down the channel to the airport.  One of the projects that did not get done is fixing the vhf radio in the cockpit so I am down below calling the port captain for clearance.  There is a funny smell, like rubber burning.  When the captain says stand by, I tell Alan about the smell and open the door to the engine room.  Smoke comes pouring out.  Alan looks at the temperature gage at the same moments and sees that the engine is way overheated.  Quickly he kills the engine and I call the port captain to tell him that we have a problem and we will not be passing the airport right now.  When I ask about the possibility of a tow back to the anchorage he says that it will be $800US per hour.  Thanks says I.  Let me get back to you about that.  We are in a busy and fairly narrow channel,  just at the end of the airport runway and surrounded by reefs. Meanwhile Alan has run forward and raised the jib sail to give us some way of controlling the boat.  I raise the mizzen and somehow we manage to maneuver into a small bay to the side of the channel and drop anchor. 

Time to figure out what happened and assess the damage.  Alan quickly realizes what happened.  The engine is cooled by saltwater and there is a valve that must be open when the engine is running to let the water in.  (It needs to be closed when we are at anchor to keep the water out.)  It was very stiff and he had only gotten it halfway open so there was not enough water to keep the engine cool.  He checked everything that he can think of and as far as he can tell there is no serious damage.  We obviously need to wait until it cools before we can start it up again and make sure it is running OK.   We will spend the night here and try again in the morning.  So here we sit.  Lunch, a drink, a nap.  We had not noticed or cared in all the excitement that there were a number of mooring balls around us.  As the day went on, fairly large commercial boats came and tied onto their moorings.  Some of them swung fairly close to us but we decided that we would be OK for the night. 

Next morning, Alan does another engine check and then starts it up.  It is noisy but everything seems to be OK.  We hoist the anchor and I call the port captain again.  Instead of the usual clearance we are told to stand by for 2 planes which means going around in a circle, avoiding the reefs until the all clear comes.  We are watching the gages like a hawk and I have the engine room door open so that I can see immediately if there is more smoke.  Eventually we are given the all clear and we head past the runway and wind among the reefs towards the main harbor.  Just as we reach the other end of the runway and just as I am about to call for clearance again a small plane takes off just over our heads.  The port captain gives us clearance and we finally clear the runway, exit the harbor and are on our way to Moorea again