antifreeze or just drain ????

[70mustang]

Greetings,I need to know if this is overkill. I have a 1999 merc 3.0 with Alpha 1 I/O.Typically on my car engines about every 5 years I flush the radiator and block with a purchased cleaner and change the antifreeze.So, is it over kill or can I harm any parts if I put the outdrive in a tube, use some block cleaner, run the engine for a while, rinse and replace the block cleaner fluid with fresh water using the muffs, and then instead of draining the water, fill the tub with some antifreeze - run the engine to circulate the antifreeze and then leave the block filled with antifreeze instead of draining the water. Your thoughts please.Marty

[Bond-o]

Hi Marty,.......You haven't included Where you do your boating,.......If you boat in Saltwater,..... Your Idea has Good Merit,......If you boat in Sweetwater,.... Ayuh,.. It's Way Overkill.......Either way,.. The Block Cleaner, Shouldn't Hurt anything,... Shouldn't being the Key Word......As for the Antifreeze thing,..... I'm a Believer,+ Promoter of Dry Storage,.... Air Doesn't Freeze,... Period........Air also Doesn't Pollute our waters either,.....If you do it Your Way,..... Make Sure the antifreeze mix is Strong Enough,+ Circulates Long Enough to open the T-stat,... Then Check the Drains to be Sure there's antifreeze Where it belongs........Or,...... Do it My Way,...... Drain Everything,....And make Sure Everything is void of water......Remember,... Air Doesn't Freeze,........And,.... Low-Tox is Still Toxic.............

[Chris1956]

70Mustang and Bondo, After I drain my 4.3 Mercruiser Alpha 1, I dump straight antifreeze into the manifold and block hoses. Quite a bit more water is pushed out by the antifreeze, eventhough the manifolds and block were completely drained and supposedly empty. If I was going to leave the block empty, as Bondo advises, I would use my shop vac to blow out the hoses, and hope the air pressure emptied the residual water in the block and manifold.

[Haut Medoc]

Every set up has its suttle nuances, ya just gotta make sure ya get the water out.......I'm with Bondo .....Dry is good!.....& Non toxic.....And free! ...JK

[WillyBWright]

I've seen arguments that unless the ice has no place to go, it won't crack a block. In other words, the small amount of water that's left behind with draining won't damage the block. I take issue with that. I've seen plenty of winch stands on trailers made out of 3" square steel tube that got water in because the plastic cap came off and when it froze, expanded the tube, sometimes even cracking it. They get fat on the bottom looking as if they're pregnant or something. But there was plenty of room above the ice for it to expand into the tube. So much for that argument! Play it safe, dump in some cheap easy-to-find RV antifreeze and sleep at night. Three bucks can save you three grand. That's AWFULLY cheap insurance.

[70mustang]

Thanks for all the advice.One of my concerns is that my block has moist air on a unprotected block. Doesn't that rust the metal. I was hoping to protect the metal with antifreeze as well as prevent freezing. Or is the rust very minimal and I shouldn't worry about it.Thansks,Marty

[DangerDan]

I wouldn't worry about the block rusting over the winter. My neighbor has had a block lying next to his garage must be over 5 years now and it's not rusted away yet. You'd think thats the only thing that would move it though...

[DJ]

Got to agree with Willy on this one.

[cobra 3.0]

Remember if you do just drain your block and mainfolds without antifreeze, that some water remains in the water pump area in the engine...unless you have incorporated your own drain plug at the water pump! Mine is basically dry except I do add some RV antifreeze from the large hose leading from the T stat housing down to the water pump. I add some anti freeze until I see it run out of the drain plugs. I leave my drain plugs off. So I guess I use a semi-dry method!

[SeaRay24Sorrento]

110 psi or more from a compessor helps to get that small amount of standing water out. I drain it dry, pull every hose and blast air into every orfice possible. Seems to have worked fine over the last 5 years using that method. Upon startup in the spring, there is minimal amount of rusty water that comes out and I don't have the mess of antifreeze to worry about. Oh yeah and it's free (well not the compressor).