Chewed up impeller. Cooling question.

[BajabossJD]

Hello,

My old impeller broke apart and I was able to replace the whole housing and impeller on my raw water pump. Everything went back together well.

I fired it up and I did have nice water flow throughout the Thru-Hull exhaust. I also had water going through the block (winter drain plug was loose and I noticed nice water coming out of it..I since have tightened it down).

However.. I did notice that the Thermostat housing had 3 cool hoses, and one really hot hose. The back half of the housing was cool, while the front was really warm.

Attached is a pic of the cool areas. (Please ignore zip ties.. I was taking the hoses on and off to check for water flow.. I have the proper clamps..)

Is it possible that I have some impeller parts stuck in housing? When I took off the large hoses, there wasnt much water in there. I even blew some air into large hose and was able to see some water gushing out of large thermostat hole.

Gauges arn't working yet..so I am unable to watch temp (reason why I havnt taken boat out yet this year).

 

[Fishermark]

Re: Chewed up impeller. Cooling question.

Is it possible that I have some impeller parts stuck in housing? When I took off the large hoses, there wasnt much water in there. I even blew some air into large hose and was able to see some water gushing out of large thermostat hole.

It is absolutely possible. Here's what I found in my thermostat housing after shredding an impeller:

 

[tpenfield]

Re: Chewed up impeller. Cooling question.

If the engine is in the initial warming stage, only the large hose(recirculating hose) will get warm first. The one opposite it is the input hose from the water pump, and the 2 rear-most hoses are the discharge to the exhaust manifolds. Until the engine (thermostat ) reaches temperature, the rear hoses will have mostly cool water as it is by-passing the engine for the most part. Once the thermostat opens the 2 hoses will have a mix of hot water from the engine and cool water that by-passes the engine to go directly to the exhaust.

the cooling flow is set up that way so that the exhaust gets water immediately and does not have to wait for the thermostat to open.

if you think that the system is not working properly, you could always inspect inside the thermostat housing as stated.

 

[dubs283]

Re: Chewed up impeller. Cooling question.

Is it possible that I have some impeller parts stuck in housing?

yes

also check any oil coolers/strainers for blockage as well