Draining engine block - Merc MX 6.2 MPI/Bravo 3

[badrano]

Yet another post from me as I learn a new engine/boat.

I see that the 6.2 has more of a single point drain system, with exception to the drain plugs on the water pump and t-stat housing. I see, what was a drain plug on the engine block of my old boat, fittings connected to hoses that connect to the hose coming off the water distro fitting. With my old engine, when I pulled the plug, I would stick a wire/coat hanger in the hole to clear out the junk so that the water could drain.

Is this something that needs to be done on the 6.2? Meaning pulling the hoses off the fittings to jamb a wire up the hole to clear the junk out?

Also, I have have the original Gen 3 Cool Fuel module. Do I need to unbolt the hose bracket so that the water drains out of that to?

So far, I've counted 4 blue drain plugs...2 for the water pump, 1 at the t-state housing and 1 at the water distro fitting....is this correct?

Are there any other hoses that should be pulled to ensure all the water has drained out? I think I've read some posts in the past where some folks don't like these new "single" drain point systems.

 

[alldodge]

Assuming open cool

The one on the thermostat housing is to allow air in so the rest will drain.
The one in the water distribution housing (WDH) is opened and all the other hoses are meant to drain down.

Now reality if it all works as designed then all good. The issue is sometimes it doesn't work as designed.

If you want to make sure, then change it from single point, to multi point, like what your other motor was

 

[Scott Danforth]

If you pull the spider manifold and hoses, you will most likely find them plugged with debris.

 

[badrano]

Thanks guys. That's what I kind of figured. Engine block drain hoses are coming off.

 

[badrano]

Well I was pleasantly surprised. Looking closer at the engine block drain hoses, they are quick-disconnects. No worries about having to pull the hose off if a barbed fitting.

 

[jumpjets]

Well I was pleasantly surprised. Looking closer at the engine block drain hoses, they are quick-disconnects. No worries about having to pull the hose off if a barbed fitting.

Mine quick disconnects on the engine block were clogged up with corrosion last year. Stuff a screwdriver into those to ensure they are clear.

 

[badrano]

Mine quick disconnects on the engine block were clogged up with corrosion last year. Stuff a screwdriver into those to ensure they are clear.

Exactly!

 

[QBhoy]

Hi
I have the same system. I use the quick drain valve to empty engine of water, then undo all quick connect fittings to make sure. But I will also say that each time, there isn’t a hint of any potential causes of blockage. This is almost certainly because I’ve always left the block full of antifreeze over winter to stop any corrosion internally. The guys that will tel you to have a poke at the drain ports to clear any flakes of rust or debris that will stop the engine draining properly, are guys who don’t leave their engine full of antifreeze. Controversial opinion for sure...but I’m sure of it. Haha.

 

[Bt Doctur]

every one I winterize has clogged engine block ports,

 

[Lou C]

Since I started using a 50/50 mix of Sierra PG antifreeze for my winterizing I have not found clogged block drains which I used to find in the past using -100 West Marine antifreeze. That stuff is also suppose to have corrosion inhibitors in it but maybe the Sierra has more because it’s actually designed to be used as an engine coolant not just for storage.

 

[QBhoy]

every one I winterize has clogged engine block ports,

No doubt because they have not been left full of antifreeze over each winter.

 

[Bt Doctur]

Ther are clogged after a season. I fill the block and manifolds with AF but even with standard plugs you will find the drains clogged. Sand, silt, rust you name it,
Best option is to remove the plugs and probe to insure it drains

 

[Lou C]

All this multi hose clog prone nonsense could have been prevented by installing even just a half system from new. For shame Mercruiser! I'd never ever install a new or reman engine without one. No way do I want to deal with crawling around in the bilge to get at the plugs or having to pull off this overly complicated contraption to just reinstall the same plugs I've been dealing with for years.

 

[QBhoy]

Ther are clogged after a season. I fill the block and manifolds with AF but even with standard plugs you will find the drains clogged. Sand, silt, rust you name it,
Best option is to remove the plugs and probe to insure it drains

To be honest...best advisory I’d think, is to fill with AF from new. If it hasn’t...the damage has already been done and results in the rust you mention, blocking drains. Better late than never though

 

[Lou C]

these are your friend for this issue, these and patience.