Tohatsu 25 4 stroke grinding noise

[Pinter Boat]

I have a 2011 25 hp 4 stroke. When the boat is loaded (with my wife and 2 small children, or 3 adults) I hear a noticeable grinding/ knocking noise coming from the area where the drive shaft meets the engine. Twice I've gotten an alarm that indicates either cooling or oil problem. Resets when I turn engine off and restart. Here's what I've checked so: lower unit oil, drive shaft/ splines, water pump/impeller, compression, engine oil, prop. All are fine. When I am in the boat alone I don't get the grinding sound; only when it's loaded. Any ideas?

 

[pvanv]

If they have the kit, your dealer can read out the memories from the ECU, and determine whether you overheated, had low oil prerssure, or over-revved. It's possible that you have a really unusual issue; I've never heard that symptom before. Could even be a sound coming from the prop area that radiates up to the motor mounts.

 

[Pinter Boat]

Thanks Paul for the quick reply. I'm down here in North Carolina, but there is a dealer nearby. I would like to get the codes read. I'll let you know what happens. Again, my thanks.