High temp at idle

[JFP]

We were out this weekend on our '86 Sunsport and I'm concerned because in neutral and when moving at near idle speed, the temp crept way up to almost 220 degrees. Once we started moving, it quickly came down and stayed down. This kept happening each time we would come to rest. Does this sound like an impeller issue? It's not a weedy lake, so I don't think the intake was getting plugged. Any ideas would be great.

Thanks.

[kcsideways]

Sounds like the impeller to me...classic symptions.

It is definitely your impellar on the water pump. These give out periodically. The beginning is to fail in this manner. At speed you are pobably foricng enough water into the engine and along with the air you are keeping up. At idle you get none of that. It is a quick fix that should take less than an hour. The key is making sure you get the new impellor in correctly so that when it turns it is pulling and not pushing water. Good luck.

[cowan4]

When you replace your sea pump impeller, lubricate it with dish soap thoroughly before installing or you will shread a brand new pump impeller. Been there, done that. NOT FUN.
cowan4

[JFP]

Just wanted to post a follow-up to my overheating problem. I pulled the impeller and one of the vanes was cracked/ripped at the base. The outer edges of all vanes looked good and the damage to the one vane did not look like it would cause a problem. However when I put the new impeller in, the cooling system now works well and is keeping the engine cool. THe moral of my post: even what appears to be minor damage to the impeller can prevent it from functioning.

PS. Used vaseline when I installed the new one and filled the lines with water to give it a good prime and it appears to have worked well.