Merc 165 heat exchanger

[hydac]

Is it possible to by-pass the heat exchanger on the sea drive cooling and run the engine with fresh lake water or will the water pump and cooling system rot out.
Thanks!

 

[jtybt]

Re: Merc 165 heat exchanger

On a lake...you can bypass the heat exchanger. You have to change the thermostat to a 143*. You will also have to re plumb the hoses and change the manifold/riser gasket...and you'll probably suffer a little worse fuel economy cuz the engine won't be be running at an efficient temp.

Is there a reason you want to by-pass the 'HE'?

 

[hydac]

Re: Merc 165 heat exchanger

Yes, The heat exchanger is leaking antifreeze to the water side. Money is on the tight side.

 

[Don S]

Re: Merc 165 heat exchanger

Is this 165 a 4 cylinder or 6 cylinder. Year would be helpful too.