Engine Cooling Question

[Just Learning]

Still new to this I/O thing---------<br /><br />Have 1997, 4.3L Mercruiser in a Sea Ray 190, raw water system.<br /><br />After running on muffs and warming engine up at least until thermostat is open, ONE side of the<br />water return is pretty warm (haven't put a thermometer to it), the other side is cool. Also, one of the risers is fairly warm (can keep had on indefinately), while the other is cool.<br /><br />Should BOTH sides and water be warm or cool?? <br /><br />Temp gauge stays constant @ 170 deg., doesn't overheat at high rpm.

 

[ed hobbs]

Re: Engine Cooling Question

It is likely that the muffs aren't supplying enough water to cool the whole system. It will usually stay cool enough to safely idle. In my case, one side was staying cooler than the other because the supply hose was lower on that side, and water runs downhill! Put it in the water and idle it to see for sure. If one side is still warmer, then you likely have a clogged manifold or riser.