How much antifreeze?

smartwork

Petty Officer 2nd Class
Joined
Jul 20, 2009
Messages
159
Mercruiser 3.0LX - I've drained the block using the side blue wing-nut and the manifold using the brass plug. Everything flowed really well and immediately and did not require wire-poking. Here on the forums and in the manual, I've read about adding anti-freeze (debated on the forums), but I never seen a reference about how much to actually put in, so that's my question. I've got the thermostat housing off and can pour straight into the hoses, but how much do you add to each hose (main and manifold)?

Thanks!
 

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
71,082
Re: How much antifreeze?

I've got the thermostat housing off and can pour straight into the hoses, but how much do you add to each hose (main and manifold)?

Ayuh,... Til Full, or you hear it leaking out somewhere....
 

WizeOne

Commander
Joined
Mar 23, 2008
Messages
2,097
Re: How much antifreeze?

....and depending where you are located, you might get away with using a 25% mix of antifreeze. They don't exactly give it away these days as you might have noticed. I also try to recapture as much of mine as I can and reuse it the next year.

25% is good down to 0 degrees.
 

joseph1980

Seaman
Joined
May 27, 2005
Messages
54
Re: How much antifreeze?

after two gallons my 3.0 started flowing out of the water pump inlet. i got some of rv antifreeze at walmart for around $4/gallon. (much cheaper than car antifreeze)
 

PeterMcG

Seaman
Joined
Nov 3, 2009
Messages
61
Re: How much antifreeze?

after two gallons my 3.0 started flowing out of the water pump inlet. i got some of rv antifreeze at walmart for around $4/gallon. (much cheaper than car antifreeze)
To be on the safe side....you might go to the manufacturer website and download the MSDS for that particular product.
For example, here is one for Zerex. With a price difference of that much, I'd hate to see you putting something in there that is, shall we say, less than helpful.

If you glance at that one for Zerex, while the exact proportions are not provided, it IS specific about its % composition of ethylene glycol and at least lists the other compounds (with a % range for each).

In all probability, things will be fine, but for 2 minutes online -- why leave things to chance?
 

BeaufortTJustice

Petty Officer 1st Class
Joined
Oct 8, 2009
Messages
248
Re: How much antifreeze?

My engine took about two gallons as well before it starting coming out...a lot of the "antifreeze" crowd actually prefer the RV stuff, not just because of cost, but for the fact that it is practically non-toxic and easier to handle and dispose of. It uses propylene glycol if I am not mistaken. It will slush up on you as it gets closer to its lower limit, but it will not increase volume.

If you do use the auto stuff, do like WizeOne and recover it for future use.
 

scbackpacker

Petty Officer 2nd Class
Joined
Aug 26, 2009
Messages
130
Re: How much antifreeze?

I got the pink Dow RV/Boat antifreeze with corrosion inhibitor from wally world to put in the 4.3 liter I have. It was about 4 bucks a gallon. I doubt if I will need it but for 4 bucks of insurance it beats what my buddy is going through with water in the oil. He fired his up for a buddy to hear the engine and forgot to drain the water back out. Boat sat all winter with water in the block. Who says it don't get cold enough in the south to crack a block?
 

smartwork

Petty Officer 2nd Class
Joined
Jul 20, 2009
Messages
159
Re: How much antifreeze?

Excellent! Thanks to everyone for the reponses. Bond-o, that helps to know that it's supposed to be "filled", and thanks to everyone else for the tips on estimates about how much "filled" takes.
 
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