PCM EX343 winterizing help please

[HutchCanada]

Vanhanbr do you pour the AF into the larger hose attachment on the starboard side of the thermostat housing as well as the two smaller hoses running to the exhaust manifolds? I think this is what the PCM manual describes

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[Tom_H]

I just drain everything, then pull off the thermostat housing cover, pull the stat and pour the anti-freeze in there. I only bring the engine up to temp prior, because I change oil at the same time, and it just drains out better when warm. I would certainly drain all the water first myself - it takes all of 5-10 minutes, and you're good. Whether or not you choose to add anti-freeze at that point is just up to you. Even with a thermostat open from being warmed up, I would never feel 100% certain that I displaced all the water and didn't just shunt most of it to the exhaust manifolds. It also can hit 50 below here in Minnesota as well, so I'm anal.

[GMLIII]

Hutch could not do this in Canada but any Nautique owners with GT- 40 engines , I never used antifreeze during the winterization process on my GT-40 engine in my 2001 Sport Nautique for 15 years and had no problems, as an alternative I sprayed Seafoam spray into the fuel injection until the motor choked off then I drained the water out of the engine. I'm not saying this is the proper procedure but it worked for me with no problems for 15 years

[jmo]

+1 on Quinner's advice to fully drain first.

The reason for this it's an open system.

If it was a 1" diameter feed throughout the engine, manifolds and outlet then it would push out the water out - this would be closer to a closed system.

the reality is there are places inside the system the water collects in a larger space where the water will churn and mix, hence there is no guarantee you didn't dilute the AF to the point of compromising the freeze protection. The exhaust manifolds are a great example of this.

If your block freezes and cracks, it's a $5,000.00 mistake.


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2006 SN 196 Limited Excalibur
2001 Super Sport Limited GT40