Winterizing - Antifreeze vs. air blow

[TheDirtyBrit]

I have my boat in my garage which is unheated and gets very cold up here in Canada (-12c today but can get down to -25c) . I’ve run the antifreeze through the system until it was pouring out the back but as it’s my first time doing it and I tend to over think things, I decided to pick up a bilge heater. It’s cycling on and off and according to my wifi thermostat in the bilge, it stays around 5-10 Celsius. One day I’ll get around to insulating the garage!

 

[Joe Starbuck]

As mentioned, in addition to draining the exhaust, you are trying to get the water out of those small metal tubes in the intercooler which is a vulnerable low point in the system.

Similar to blowing the water out of anything else, you need a goodly volume of air going through there at full pressure.

I use 100+ PSI air with a short, 5/8" hose connected directly to the air compressor tank with a ball valve that can be opened (not through a regulator or long small dia. hose). Connect the air and open the valve and let it blow until the tank is depleted down to 30 PSI or so. I close the valve and let the compressor catch back up to full pressure in the tank. That also lets any remaining water collect back into one place in the low spots. Then I open the valve for a second burst of full pressure air which will push any collected water through the low spot. After three cycles of that, I don't hear any water bubbling inside, so it seems to to get the water blown out.

Agree that high volumes of air are helpful. Referring to the plumbing diagram in these engines, if you put air in the flush connection there are two ways for it to exit the boat. The first is into the exhaust system and out the exhaust port low on the transom. The second path is backwards through the cooling jacket of the exhaust manifold, then backwards through the intercooler, then trough a longer hose to the jet pump, then out to the atmosphere. The first path is the path of least resistance. I found that I could block the exhaust port with my hand while opening the air valve. This forces all the air to go through the intercooler and out the jet pump. I think it is helpful, and it is going down to 8F tonight, so I will keep my fingers crossed!

 

[briancayko]

Chiming in from NYC. I think water is not as much of an issue if you winterize early. I did in early NOV in Staten Island. Gravity fed -50 Pink RV antifreeze though the hose next to the jet pump threw a gallon thought the system it was all pink on the way out. Any water left in the system I would assume evaporated over the month and a half of above freezing wx. The oil change will be done in the spring so fresh oil is running though the summertime. For protection I just put my cover on it. No shrink wrap. Spot cleaning any mildew that pops up after rain. No snow yet.

I was taught to change the oil before winterizing otherwise the dirty oil “settles” & all the dirt sludges to the bottom of the pan & doesn’t drain out as well several months later. Probably only an issue if you have a lot of hours on that oil but I’m interested to hear others thoughts?

 

[Joe Starbuck]

I was taught to change the oil before winterizing otherwise the dirty oil “settles” & all the dirt sludges to the bottom of the pan & doesn’t drain out as well several months later. Probably only an issue if you have a lot of hours on that oil but I’m interested to hear others thoughts?

I change it in the fall. Used oil has more acid and water than fresh oil, so over the winter I have less acid and water in my engine. Added benefit is “ready to go” status in the spring.

 

[briancayko]

When pumping in the antifreeze, I’m using a drill pump, I clamped off the hoses that the manual says to clamp when towing, I figured that when the engines are off there is a risk of pumping fluid into the engines otherwise. Does that sound right or am I misunderstanding the flow?

Thanks!

 

[DooGuy]

When pumping in the antifreeze, I’m using a drill pump, I clamped off the hoses that the manual says to clamp when towing, I figured that when the engines are off there is a risk of pumping fluid into the engines otherwise. Does that sound right or am I misunderstanding the flow?

Thanks!

The main purpose of the rv antifreeze is to get anyplace that had water during operation. Should use low pressure air to blow moisture out first. My process, I have the 215 scic internal intercooler. I pump in with engine running using the hose flush port and run until comes out the jet for a few. Same process as if you were flushing with garden hose except Antifreeze vs water. I want to make sure there’s a healthy amount in the exhaust and intercooler etc. does that help?

 

[briancayko]

The main purpose of the rv antifreeze is to get anyplace that had water during operation. Should use low pressure air to blow moisture out first. My process, I have the 215 scic internal intercooler. I pump in with engine running using the hose flush port and run until comes out the jet for a few. Same process as if you were flushing with garden hose except Antifreeze vs water. I want to make sure there’s a healthy amount in the exhaust and intercooler etc. does that help?

Perfect. Thank You

 

[jouan]

I am also searching about this topic blowing Out RV Water Lines vs Antifreeze