Engine getting hot!!!

[Bellinghamster]

My first time out this season I heard squealing while idling away from the launch, shut down to investigate - the raw water pump was too hot to touch! It failed to prime due in part to the hose loop above waterline out of the transmission cooler, and possible because I'd drained the block and the heater hoses - I've got a "T" heater return to the suction side of the raw water pump. With the block empty it was pulling air from the block/exhaust backwards through the heater and into the intake of the water pump. I swapped impellers (for good measure), poured water into the hoses to fill them up, pinched off the heater circuit hose and fired back up - no problem. I should have run it on a garden hose first to fill everything up with water before launching...

[tchipman]

sounds like impellor or clogged oil cooling line?

[gwpowell]

We had a similar problem but it turned out to be the fresh water flush kit which was fitted to the intake side of the water pump. The hose was rubbing on the alternator pully which wore a hole in it.
It was difficult to spot because when the engine hatch was open the hose was not against the pully, it was only after we closed the engine hatch that the hatch itself pushed the hose against the pully.

At speed we were OK because the flow of water into the pickup had enough force to push itself through, but at idle the impeller was sucking air from the hole in the hose so we overheated.