So I replaced my impeller for my water pump the other day and figured while I had everything pulled apart I'd dig even deeper and replace more things that could use replacing. I decided to order a new Thermostat housing and replace that, when I pulled of the hosing I got a lot of rust particles out of the hoses. Is this a sign of a bigger problem or am I doing the right thing be replacing what I have. The engine is a commander engine but it's most similiar to the Mercruiser, so I plan on using this section of the forum for advice. It's my first boat so I'm trying to learn.