PCM DI Engines- To Antifreeze or to NOT antifreeze

[Kmayotte]

After reading several conflicting recommendations online I asked several contacts in the industry about whether I should use antifreeze to winterize the 2016 H6 450 in my G23. The consensus seems to be in the more southern states a simple drain and dry storage with the plugs out will suffice. Antifreeze is a good idea in northern state where the winter temps are much lower for added peace of mind.

The response from a rep at PCM:

The use of Antifreeze to flush the engine before storing for the winter is
always a good idea but not required provided all the drain plugs for the raw
water system are removed and left out during storage.

The idea is to get as much of the raw water that you can out of it to
prevent freezing.
Sometimes pockets of water can still be in the engine but in most cases with
the drain plugs removed they do not present a problem.

Addition of antifreeze into the engine right at the winterization period
does add some added piece of mind that any pockets of water not removed will
have some antifreeze in them.

I think my tactic will be to flush the engine with antifreeze and then remove the drain plug. That way any pockets of liquid left in the engine are antifreeze.

Waiting on a response from PCM if there is an official recommendation on the type of antifreeze.

[DaveNH]

A better method is to drain the water first, then add antifreeze. You want the block as empty as possible before adding the antifreeze. So pull all the plugs to drain the water, then replace them, pump antifreeze through the engine until it's coming out the exhaust.

As a disclaimer I know nothing specific about that engine, this is just a good general method.

[Quinner]

Definitely drain first before adding any anti freeze!! If you use the pink anti freeze avoid the ethanol based stuff, the -75deg stuff usually is propylene glycol which is what you want to use.

[Nautiquehunter]

This is what I believe and do even though I moved to Georgia 6 years ago. I like the drain then fill method when I was in Indiana I used 50/50 green antifreeze giving protection to -30 . Here in GA I cut back to 30/70 giving protection to -5. I don't like dry storage for two reasons first when dry the inside of the engine will rust and form scale and I don't want the normally wet gaskets to dry out. Second if you just drain there is no way you can be sure you got all the water out . Any water that gets trapped can spell disaster.With new engines in the 10,000 dollar range it seams silly to chance it with dry storage.

[keithh2oskier]

I am in an area fortunate to not have to worry about winterization - at least at the freezing point as my garage rarely would dip into the high 30s. We have always put away our boats like we do after every weekend without any noticeable issue. I dont drain the block or add any coolant for freeze protection. Is it okay to essentially leave lake water in the cooling jackets for the winter or will that in itself cause issues. I imagine its better than leaving it "dry" where rust can form but perhaps its not.

Any recommendations? I am open to looking at an alternative winterization process other than oil change and trickle charger.

[jmo]

This is what I believe and do even though I moved to Georgia 6 years ago. I like the drain then fill method when I was in Indiana I used 50/50 green antifreeze giving protection to -30.

Just make sure to remove the green car antifreeze from the system and dispose of it properly before you launch in the Spring as its toxic...


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[DocPhil]

I already winterized mine and I'm dry blocking it. I see no reason to add antifreeze.

Don't forget to blow out your heater hose.

If you do add antifreeze please post a pic of where you added. I might have a sudden OCD attack in December

[Nautiquehunter]

Docphil I went over the reasons to add antifreeze in my post above . If you feel confident with drain only then go for it. I would make sure you have freeze coverage on your insurance living in Michigan. You already did most of the work when you drained the block on my 08 350 I remove the raw water hose at the top of the trans cooler and block it off then remove one of the hoses at the thermostat housing and fill until antifreeze comes out the exhaust .

jmo I always run my boats before I put them in water in the spring I use a 5 gal bucket to collect the antifreeze.

[DocPhil]

Docphil I went over the reasons to add antifreeze in my post above . If you feel confident with drain only then go for it. I would make sure you have freeze coverage on your insurance living in Michigan. You already did most of the work when you drained the block on my 08 350 I remove the raw water hose at the top of the trans cooler and block it off then remove one of the hoses at the thermostat housing and fill until antifreeze comes out the exhaust .

jmo I always run my boats before I put them in water in the spring I use a 5 gal bucket to collect the antifreeze.

Freeze protection? In Michigan? I don't think there is such a thing. It already froze here...LOL