antifreeze in thermostat housing

would it be safe to drain out

would it be safe to drain out the block and manifolds of water and then replace the plugs then pour -50 antifreeze in the motor through the thermostat housing to winterize the motor? ty Darrin

There are many ways to add ant

There are many ways to add antifreeze to the engine; just an individual's preference as long as all the water is out and replaced with a sufficient quantity of antifreeze in every nook and cranny.

I do mine in a manner similar to what you are contemplating. I disconnect every hose at the T'stat housing and then do the following:

Bend the large hose to the circulating pump downward to drain trapped water and then pour in 1 gallon of antifreeze; reconnect hose to T'stat.

The other 5 smaller hoses are each treated with a minimum of 1/2 gallon each and reconnected. Make sure antifreeze comes out the exhaust or add more to the exhaust manifolds.

"Not to detract from Guy's

"Not to detract from Guy's method, but if I were going to the trouble of an antifreeze flush I would want to make sure it displaced all remaining water by pumping it though the engine.
I would disconnect the water inlet hose where it connects to the T'stat housing and hook up a pump and hose to pump antifreeze into this connection from a supply bucket.
Once it comes out of the exhaust you know you have everything full of antifreeze. For my money this would also be a whole lot easier method.
You could use a drill pump or a hand plunger pump like those used for changing the engine oil through the dipstick.
The only other concern is that the water supply hose from the water pump (be it an Alpha leg pump or Bravo belt driven) needs to have the water drained from any low spots such as the PS or engine oil cooler.
Rod"

Hey Rod:

No feelings hurt h

Hey Rod:

No feelings hurt here. I like you method better than mine and I have a drill pump to use. Somebody always has a better idea on this board. Thanks.

"Guy;
Glad you took that in t

"Guy;
Glad you took that in the intended context; I sure don't want to upset the apple cart.
For what it's worth, I have never done an antifreeze flush in 25+ years of boating. I have always just done a thorough draining as part of winterizing, and nothing has frozen yet. Does that mean I am smug enough to think it never could? No way! I am sure that the antifreeze flush is better, and Merc recommends it also.
I may start adding the flush to my winterizing regime, as it would be very sad to freeze up the new 383 just for lack of some antifreeze.
I have not been on the board for a while; what's new?
Cheers,
Rod"

"Do I know you? <[img]"http:/

"Do I know you? Oh yes; now I remember you. Did you take another vacation? You sound like a man that would go over Niagara Falls in a barrel. I have seen -45 C. here in SW Ohio several times so I don't take the chance even though I drain my block and mans. right at the lake; the water is HOT! so I hope the block and mans. dry out on the ride home. I haven't winterized yet except for draining the water last time out in case the forcast calls for freezing weather."

"Yes I guess I like to live on

"Yes I guess I like to live on the edge a little. But I'll pass on Niagara.
-45 C in Ohio??? Yikes, that is chilly. About the coldest it has been here in southern Alberta any winter recently is about -35; and then it only lasts a day or 2. No matter, even a few hours of -5 C will freeze and destroy a block if there is any water left in it, so best to take all appropriate precautions.
We were in Orlando for 12 days with my wifes son and grandchildren. Wow, I am Mickey'd out for life! The rides were lots of fun though. Nice and warm and humid.
Kennedy space center was great.
Cheers for now,
Rod"

That is where we went last Mar

That is where we went last March. Spent 3 days each at Disney and Cocoa Beach. Sun was very warm and temp was 80 F. w/strong breeze.

"I guess I should feel fortuna

"I guess I should feel fortunate that I live in a warm Southeastern climate; we might see 18-19F for a couple of nights out of the year.

I'm a new boat owner, but I figure that I'm OK just draining the cooling system, since the boat is in my garage which never gets below 45 degrees even in the coldest Tennessee weather."

""we might see 18-19F for

""we might see 18-19F for a couple of nights"

"I figure that I'm OK just draining the cooling system, since the boat is in my garage which never gets below 45 degrees."

When the temp. drops below freezing occurs, you are taking a chance with $4,500 on the line. It's a coin flip. Heads (no frozen block) you win $0. Tails (block freezes) you lose! What if the garage door gets left open? Put $10 worth of anti-freeze in the engine; cheap side bet."

Good point

The only reas

Good point

The only reason I didn't want to do so is that I've already fogged the engine and didn't want to crank it again to circulate antifreeze through the block. However I think I did read in a post of yours in another thread (and some input from Rod Stewart too) that you can pump antifreeze through the thermostat housing for almost the same effect.

There are numerous procedures

There are numerous procedures to prevent engine freeze damage; take your pick.

"Just letting you guys know, I

"Just letting you guys know, I added antifreeze last night. It must have been quite a while since the thermostat hoses have been pulled, as it was a real struggle to get them off.

I hope that I did things right....I poured about a gallon of the pink stuff down the largest hose connected to the thermostate housing, and about a third of a gallon each for the other three. In the end there was some running out of the exhaust."