Flushing a 5.0 mercruiser

[jorgeoliva]

just to settle an argument I have a 2000 mercruiser 5.0 -8 cylinder engine when I come back from a day in the water I put the earmuff on the outdrive and I run the engine for 5 minutes to flush it, my buddy says that you do not remove all the salt from inside the engine and it's best to use a tube that splice into the water hose like the one they sell to flush the radiator in a car that you can hook up the water hose directly to it, I disagree. any input is appreciated

 

[nickmo]

As long as the thermostat opens, the fresh water is flowing through the engine.

 

[jorgeoliva]

but if water is coming out thru the outdrive exhaust does this mean that fresh water is flowing thru the entire engine

 

[Leardriver]

Part of the engine is blocked off by the thermostat, so that the engine will warm up faster.
As nickmo stated, when the thermostat is open, then you are flushing the entire engine.

 

[jorgeoliva]

I'm not much of a mechanics but how do I know when the thermostat is open

 

[Fishermark]

The engine needs to warm up to operating temperature before the thermostat will open. Water will always flow out the exhaust, but it will only flow through the engine with the thermostat open. If it makes you feel better with your argument with your friend - - you do not need to put a "tee" in the hose to flush the engine. And if you simply put a "tee" in the hose and connected it to your garden hose you would not flush the engine at all without it running as the thermostat would remain closed. (And if you ran it that way you would burn up the impeller in the drive).