How Many Drain Points Should There Be?

[jayhanig]

I have what I believe to be a 1998 GM Mercruiser 3.0 liter engine, serial number 1M07188RX, which is a straight 4 cylinder built in Mexico. I bought it as a long block and my engine guy assembled it with a combination of new and almost new parts from a boat with a known history. One of the things I ended up with was one of those t-handle gadgets which allows me to drain two coolant drains without getting in up to my elbows in engine. It leads me to believe that there are only those two drainage points: one for the block; one for the manifold but other things I've read have made me doubt that. I have one service manual which suggests there are a total of four drains: one on each side of the block and one on each side of the manifold. I don't know. I am reluctant to just start pulling plugs willy-nilly.

How many drains are there on this engine? I've been paying somebody to do this for me the last three years because I've been afraid my ignorance might cost me another engine. Still, I'd get more utility out of the boat if I could use it right up until when it's supposed to freeze overnight without having to worry about getting on somebody's work schedule. My boat lives on a trailer in the driveway; not in a boat slip.

 

[Bt Doctur]

on a 4 cylinder rwc cast iron block there are only 2, the block and the manifold . disconnect the hoses and make sure something does drain . if not remove the hoses from the block and manifold and probe the holes with a wire or drill bit to make it drain.
The "V" motors have one drain on each side of the block and 1 drain in each of the manifolds

 

[Bondo]

on a 4 cylinder rwc cast iron block there are only 2, the block and the manifold . disconnect the hoses and make sure something does drain . if not remove the hoses from the block and manifold and probe the holes with a wire or drill bit to make it drain.
The "V" motors have one drain on each side of the block and 1 drain in each of the manifolds

Ayuh,..... Those hose systems give ya a false sense of security, in that ya never know if the block, or the manifold, or both, Might have drained,...

Ya really oughta pull that entire contraption off yer motor, 'n get 2 simple brass pipe plugs to use,....
The block is 1/4" pipe, 'n the manifold is either the same, or 1/8" pipe,....
The 1/4" plugs take a 9/16" wrench, the 1/8", a 7/16" wrench,...
Leave a deck screw in the pocket of the intake manifold, that way you can poke the crud outa the drain holes, 'n be S U R E it's freeze Safe,....

 

[jayhanig]

Thanks, guys. It just seemed too easy. I'm going to warm the engine up to normal temp on the muffs, drain the block and manifold, then start the engine with the muffs again, this time running 5 gallons of antifreeze in. When it starts getting close to running out of the antifreeze, I'll start fogging it and choke it out with fogging oil. I'm inclined to pull the spark plugs and add some fogger there as well, one at a time. Finally, drain the block and manifold again. Sound like a plan?

I can't count the number of times I've read "air doesn't freeze" but I still have some trepidation of leaving those areas dry over the winter. I live 200 yards from the ocean and worry about internal rust. I do run Salt Terminator religiously after every use of the boat.

 

[Starcraft5834]

sounds like your in good shape Jay...... "air dont freeze":drum: badaboom! the extra pink coating and draining probably not necessary... with that said....if you like the coating, have at it........last winter up here in the north east was brutal! I stored dry...my old 3.0 ran very nicely all season...I did the exact same procedure, I like you worried last winter,, this winter,,,,na.. will sleep like a baby