Seadoo 255 coolant overflow

[Nachoranf]

Hi, i went for a ride today in my boat and noticed only one of the engines coolant reservoir cap was loose. (since i recently bought the boat it was probably left like that by the last person who worked on it).

I proceeded to screw the cap on as intended and rode for approximately 20 min, when arriving to the dock, that same engine threw an overheating light, i turned it off immediately and docked, when i checked the bilge the coolant reservoir was almost empty and the bilge full of coolant (it seems to have come from the overflow hose).

I wanted to know if anyone has had something similar happen or at least has some guidance on what the cause might be.

thanks in advance.

 

[Milehighguy303]

You may want to post in the boat section for specific feedback on a boat set up. But There are probably a couple possibilities… you could have an issue causing the engine to overheat and burp out coolant from the overflow as the coolant expands. Or you could have a leak in the cooling system, and with much of the fluid in the hull, the engine then overheated because you don’t have effective cooling.

I think if it was me, I would try to fill my cooling system with water and then pressure test it with one of those cooling system pressure testers - maybe a car parts store has one they can loan you that fits the Seadoo coolant reservoir cap? And check all my hoses and clamps for any leaks with 10-15 psi. If it will hold pressure steady for 15 min or so, you likely don’t have any leaks.

If no obvious leaks, then you will have to go further into cooling system diagnosis.

 

[Nachoranf]

You may want to post in the boat section for specific feedback on a boat set up. But There are probably a couple possibilities… you could have an issue causing the engine to overheat and burp out coolant from the overflow as the coolant expands. Or you could have a leak in the cooling system, and with much of the fluid in the hull, the engine then overheated because you don’t have effective cooling.

I think if it was me, I would try to fill my cooling system with water and then pressure test it with one of those cooling system pressure testers - maybe a car parts store has one they can loan you that fits the Seadoo coolant reservoir cap? And check all my hoses and clamps for any leaks with 10-15 psi. If it will hold pressure steady for 15 min or so, you likely don’t have any leaks.

If no obvious leaks, then you will have to go further into cooling system diagnosis.

Thanks for the insight, I posted here because the cooling system in the boat is the same as the one on most of the closed loop sea doos. I will check with a pressure tester as soon as possible, however i was wondering whether the leak right after placing the cap could be indication of something. I am also considering performing a leak down test on the cylinders to check for head gasket leaks.

 

[skiasylum]

Hi, i went for a ride today in my boat and noticed only one of the engines coolant reservoir cap was loose. (since i recently bought the boat it was probably left like that by the last person who worked on it).

I proceeded to screw the cap on as intended and rode for approximately 20 min, when arriving to the dock, that same engine threw an overheating light, i turned it off immediately and docked, when i checked the bilge the coolant reservoir was almost empty and the bilge full of coolant (it seems to have come from the overflow hose).

I wanted to know if anyone has had something similar happen or at least has some guidance on what the cause might be.

thanks in advance.

I think you are right the cap was left loose intentionally to keep the coolant system from overflowing from over pressure in the system. Especially since the boat was just sold. Aren’t sellers grand. There are like 12 reasons why coolant can overflow out of the reservoir. Google it.