4.3GL Engine draining ports

Marble13

Cadet
Joined
May 2, 2020
Messages
15
So I am about to winterize my boat and was curious where all the engine draining ports are located. I have found the two on the manifold as well as on each side of the block. Is there any other draining ports?
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,802
if its a vortec engine (8 bolt intake) there is a drain plug on the front left side of the intake manifold as you face it.
you also disconnect the lower end of the big hose that connects the front circulating pump and the thermostat housing, let that drain
and the hoses on the impeller housing (mark them do not mix them up; one goes to the transom mount and one goes up to the thermostat housing) I'd also hold the hose that goes from the impeller housing to the transom mount up, with the outdrive down and pour Antifreeze (Marine PG antifreeze) in the hose till it runs out the drive water intakes; this will push water out of the hose and the P/S cooler on the back of the engine, the drain on that is very hard to get at.
Engine block drains, poke them with a pick or thin screwdriver. Manifolds do the same. Engine holds about 4 gallons of liquid, each manifold holds approx 1/2 gallon or so. If you're not getting this much out make sure to really poke and rod out those holes.
 

Radlingerb

Recruit
Joined
Oct 20, 2020
Messages
1
I'm in the middle of winterizing. Had to come back home to get a female plug socket for the drain on the front of the intake manifold (seems like that plug hasn't been removed in quite some time). Going to finish the job tomorrow, but wanted to verify I'm getting everything.
Are there plugs to drain each exhaust manifold? The manual I have doesn't mention them. I disconnected the hoses at the front of the manifolds and drained there, reconnected, then disconnected at the thermo housing and dumped in -100 AF.
I also got both block drain plugs, the hose to the circulating pump, and both hoses on the seawater pump (from the schematics that gets the steering oil cooler as well?).
Sounds like along with finishing draining the intake manifold, I should flush the seawater pump to transom mount house with AF so it flows out the drive intakes?
Thanks!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,297
one on each block side, each exhaust manifold, the intake manifold as mentioned, the large J hose on the front, pull the raw water pump cover and drain the line to the PS cooler
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,802
For the manifolds it depends on if they are OE or aftermarket, but usually on the Volvo style manifolds there is the water intake port on the front and on the back side in the same spot there is a drain plug. Some OE Volvo ones have a plug in the middle of the underside of the manifold. If you removed the feed hoses that will drain it the same as the plug, as long as the engine was level.
Since there is a power steering cooler in line with the transom water hose, but its way on the back side of the engine, I would disconnect that hose at the impeller housing, put the drive down, hold the hose up and fill it with -100 AF till it runs out the drive intakes. Reconnect and you're done.
 
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