Cooling Problem - 3.7L 165 hp

[nh18ucoach]

I have just bought an old Four Winds ski boat with 165 hp 3.7L. This boat uses a heat exchanger to cool the internal water with lake water. The boat runs fine and temp stays around 170 for a while but pressure seems to build up and temp guage closes in on the redline. I (carefully) open the internal water tank and see I have lost most of the water in the internal top holding tank. The water in the plastic overflow resevoir is nearly boiling. I have inspected all water hoses looking for indications of where it might be leaking but no luck. After allowing it to cool down some I replace the missing water and my temp returns to 170 and will stay there for about 30-45 minutes of driving.

Anyone have an idea?

 

[nh18ucoach]

Re: Cooling Problem - 3.7L 165 hp

Ok - since no one has posted a response to my initial question let's try another question.

Can anyone point me to a good boat mechanic in the Nashville, Tn. area that has experience working on 3.7 L (closed cooling system) boats? I think we are looking at a head gasket replacement and possibly other repair once inside the motor. Any help would be appreciated.

 

[beakerrc]

Re: Cooling Problem - 3.7L 165 hp

I had a coolent problem also. I replaced the raditor cap and it's been fine since