Random overheating and water in boat

[LTtige22v]

I have a 03 22v with the merc 350 mpi in it. I get an alarm for overheating randomly. Had the impeller replaced but still get the overheat randomly. If i shut the boat off then start it back up, normally runs fine no over heat. I also notice when it over heats there is water in the bilge, I don't know if this is linked. I did have one of the quick connect water hose come off one time so i connected it back up. This hose connected to a manifold under the motor it was a 1/2 inch line. Connected it back up and was fine. So I plan on replacing the thermostat and flushing the intake out to see if something is in it. Looking for any other answers and help. Thank you in advance.
Chad

[JLG]

have you made sure that there aren't any parts of that impellor or an old one that is blocking the flow anywhere in the system? My 20i shot an impellor a few years back and I had to go through the entire cooling system pulling hose by hose to get pieces out. Most of the pieces were in the (metal cooling tube don't know the correct name for it) that has slotted holes looks like a pistol revolver on the inside though, and it was stuffed full of rubber pieces. Maybe a faulty sensor or maybe the new impellor isn't working properly and is sticking in the water pump as I've seen my 20i do this on occasion if the impellor would get dry even new impellors. Usually when it stuck, the pulley would stick also and cause the belt to squeal. I would change the impellor yearly as it left me stranded once.

[chpthril]

On a Merc, I would pull the trans cooler and flush it first thing. Next would be to inspect the impeller housing if its the composite one. They get warped and scared inside.

[LTtige22v]

have you made sure that there aren't any parts of that impellor or an old one that is blocking the flow anywhere in the system? My 20i shot an impellor a few years back and I had to go through the entire cooling system pulling hose by hose to get pieces out. Most of the pieces were in the (metal cooling tube don't know the correct name for it) that has slotted holes looks like a pistol revolver on the inside though, and it was stuffed full of rubber pieces. Maybe a faulty sensor or maybe the new impellor isn't working properly and is sticking in the water pump as I've seen my 20i do this on occasion if the impellor would get dry even new impellors. Usually when it stuck, the pulley would stick also and cause the belt to squeal. I would change the impellor yearly as it left me stranded once.

Thanks The impeller was in one pice when it was pulled out. But i will look into the hoses .

[LTtige22v]

On a Merc, I would pull the trans cooler and flush it first thing. Next would be to inspect the impeller housing if its the composite one. They get warped and scared inside.

Thanks The dealer replace the impeller I dont know if they check the housing. I will check it. I will back flush the cooler. Thanks for the info