Winterizing 2010 Mercruiser 4.3L 190HP V6 Alpha One

[Michael Bel]

Filled the block and maniflolds this fall by first draining the water pump, block, and manifolds of all water, and then taking off the manifold bypass hoses and water circ pump hose, and then filling with RV fluid. My question is whether of not the raw water intake hose coming from the impeller is self draining, or if that hose should be removed at the thermostat and then backfilled with rv fluid. My understanding is that there is a power steering cooler in this line that may need protection. The manual does not mention this hose in the instructions for winter storage. Also, if you do not remove the line from the thermostat, is water retained at the thermostat that may cause a breakage or leak at freezing temps?

 

[Bondo]

My question is whether of not the raw water intake hose coming from the impeller is self draining,

Ayuh,.... Welcome Aboard,... Nope, that hose is not self-drainin',....

I pop it off the P/S cooler when I winterize mine, Dry, no anti-freeze,....

Air don't freeze, why waste anti-freeze,..??.....

 

[Michael Bel]

Hey Bondo, thanks for the welcome and prompt response. I guess I would ask if wasting a little antifreeze is an effective alternative, poured in from the thermosat hose connection. Not sure I can reach the power steering cooler on my boat, and if so, how much effort that would entail in terms of reaching and bodily contortion, profane expletives, etc. I'm getting a little long in the tooth and maybe a little personally overweighted for that kind of exercise. Is the cooler located at the rear of the engine? Horizontal orientation to the ground? Surprising to me that the manual does not mention it needing any special attention. Seems I've read somewhere, maybe on this site, that in the newer engines the cooler has a vertical orientation, to provide for self draining.

 

[Lou C]

If there is a PS cooler in a spot you can't get at then disconnecting that raw water intake hose at the thermo housing and pointing it down in the bilge will drain most of it. Lower the drive first that allows water passages in it to drain as well. I will the put a funnel in the hose and fill it with -100 marine AF till it runs out the water intakes just to be on the safe side. Then re connect the hose. The ps cooler on my OMC is on the back of the engine & the drain on it was very hard to reach until I changed the exhaust on my engine from the one piece bat wings to the Volvo style center riser exhaust that gives more room around the engine...

 

[Michael Bel]

Thanks Lou, appreciate your input! Yes, I was thinking of just disconnecting the intake hose at the thermostat, draining, and then pouring the 100 rv fluid back toward the cooler. My thought was that there should not be anything that would prevent the rv fluid from flushing the cooler doing it that way. After checking a pic yesterday of a rear-view 4.3L 190hp Merc, it appears the cooler is mounted in the rear of the engine. Tough for me to reach, so will go with the disconnect at the thermo. Seems to me that if I am winterizing using this method (disconnecting hoses, and filling with rv fluid, as opposed to sucking in rv fluid from a container), it may be wise to go ahead and disconnect that intake thermostat hose anyway, just to make sure there is no water in it that is near or actually inside the thermostat that could freeze.