johnnybass
Cadet
- Joined
- Jun 19, 2011
- Messages
- 29
A friend of mine just picked up a 1973 cobalt tri hull with a 302 ford engine with a mercruiser 888 outdrive. anyway the boat has been sitting quite a while and the history is unknown. what i can say is this.
We replaced the impeller first thing before doing anything else
Second thing was we checked all the water drains on the motor(they were all open !)
so I think who ever had the boat before had winterized it!!
anyway we fired it up and it started just fine and ran for a few minutes with the muffs on it, but it seemed to be getting a little warm (probably a stuck thermostat ) and this point we shut her down and i thought I would check the oil, perfect clean as a whistle!!
then we decided to take out the thermostat and see if it was any good( it was bad)
any way we decided put it back together without the thermostat and put the muffs back on and run it again.
within ten minutes of firing it back up i noticed frothy oil coming out of the oil cap on the valve cover. so we shut it down checked the oil dip stick and same thing water in the oil.
What has sparked my curiosity is the fact that before we pulled the thermostat there was no water in the oil, after pulling the thermostat it is mixing water in the oil. we live in northern nevada and it is not uncommon to see boats with cracked blocks, but givin the fact that the all the drains on the motor were open and it seemed that it had been winterized i really don't feel that the block is the problem.
I know a pressure test is the first thing i should be looking into but I also know tha these ford motors have these allen plugs in the cylinder head that could have rusted through and could be causing the problem(one of the local lakes is Pyramid and it is alkaline lake giving the same problems as salt water would)
Typically i would tend to think cracked block but with different results from removing the thermostat i am leaning towards the top end of the motor and not the block itself, any tip and tricks to pinpoint this issue would be great.
We replaced the impeller first thing before doing anything else
Second thing was we checked all the water drains on the motor(they were all open !)
so I think who ever had the boat before had winterized it!!
anyway we fired it up and it started just fine and ran for a few minutes with the muffs on it, but it seemed to be getting a little warm (probably a stuck thermostat ) and this point we shut her down and i thought I would check the oil, perfect clean as a whistle!!
then we decided to take out the thermostat and see if it was any good( it was bad)
any way we decided put it back together without the thermostat and put the muffs back on and run it again.
within ten minutes of firing it back up i noticed frothy oil coming out of the oil cap on the valve cover. so we shut it down checked the oil dip stick and same thing water in the oil.
What has sparked my curiosity is the fact that before we pulled the thermostat there was no water in the oil, after pulling the thermostat it is mixing water in the oil. we live in northern nevada and it is not uncommon to see boats with cracked blocks, but givin the fact that the all the drains on the motor were open and it seemed that it had been winterized i really don't feel that the block is the problem.
I know a pressure test is the first thing i should be looking into but I also know tha these ford motors have these allen plugs in the cylinder head that could have rusted through and could be causing the problem(one of the local lakes is Pyramid and it is alkaline lake giving the same problems as salt water would)
Typically i would tend to think cracked block but with different results from removing the thermostat i am leaning towards the top end of the motor and not the block itself, any tip and tricks to pinpoint this issue would be great.
