Putting In Anti-Freeze

[Dave 205]

I finally read my Mercruiser manual in detail on winterizing. I think I may tackle this myself.

I apologize if there is a good thread on the 5.0 - at least I did a little looking.

I've got the 5.0 with the carb. It appears I have the 3 point manual drain system, and I'll be draining it on my trailer. I don't see anything that indicates I have an air actuated single point system. And, If I'm wrong it appears that the three point is the back-up anyway.

Finding the plugs and twisting them out is easy enough. I've seen the threads on adding anti-freeze via muffs, but I think I'd prefre to pour it in top down.

Where the dumb questions start: There is a T-structure at the front top of the engine. Is this the t-stat housing? Do I dismantle this and put the anti-freeze down this? I think I've seen comments here to put anti-freeze in full strength, but the manual talks about mixing it to manufacturers recommendations. Plugs in or out while doing this?

Adding anti-freeze is not covered in my manual but for a confusing statement saying that anit-freeze is "for additional assurance," followed by a bold paragraph saying anti-freeze is required.


Thanks!

 

[paulswagelock]

I believe there have been lots of posts on here about winterizing lately - you do not need one specific to your engine.

If you have a 3 point system, drain it completely and put the plugs back in. The tstat housing is front and center on your engine, with a large 2" diameter hose and a few smaller ones. You can remove each hose and pour in antifreeze. I suggest you go online and look up your engine's cooling system schematic and understand all the flow paths. It might not be evident without that whether you have the entire system full of antifreeze with just those hoses. On my 5.7 that would not get everything.

It will take 5 gallons or so to do it. I have found it easier to run on muffs until AF comes out the exhaust, then manually fill the block by pouring it in. That is the fasted method for me. This year I used a small baby pool and submersible pump. 6 gallons AF in the pool, connect the muffs to the pump, and start the boat (drained engine first). After 4-5 minutes I was at operating temps, shut down. Pulled the hose and poured a few ounces in and a few ounces came back out the tstat housing - completely full system. Very quick and simple. Pump was ~$29.