Raw water circulation question/help....

[nwboater45]

I have a 1989 Mercruiser 470, 165, 3.7L. I have an issue somewhere in my raw water cooling. Right now I have water leaking or should say being forced out the back gasket of the heat exchanger. I pulled the front inlet and there is lots of water going in. I pulled the hose from the power steering riser to the exhaust manifold and no water going through that outlet. I just got back from the radiator shop and they looked at it and said there is no blockage. So now I am stumped. Where should I look next? I have flushed out the exhaust riser and there is no blockage there. What could it be?

 

[Bt Doctur]

leaky gasket from poor winterization? from the drive thru the reg thru the heat exchanger thru the ps cooler and out the riser.

 

[nwboater45]

Are you talking about the gasket at the exhaust elbow to the manifold?

 

[Bt Doctur]

on both ends of the HE are end plates with rubber gaskets

 

[nwboater45]

I just replaced both end gaskets on the HE. Since it was leaking at the end gasket that is the first thing I changed. Also I checked both end plates and both are flat. I also pulled the PS cooler and no blocks there and then the riser. Nothing blocking in the riser either.

 

[Bt Doctur]

\
if you have no water exiting here , you have no water entering the heat exchanger

 

[Bt Doctur]

raw water flow

 

[nwboater45]

Thanks BT.....I am going to start reassembly in the morning. I know I have good flow going in but it was blowing threw the end gasket. If it doesn't work then I will post some photos or vids. The only thing I don't have in the diagram above is the drain plug in the cooler. I looked for that last night after I searched through the service manual.