Strange exhaust behavior during winterizing

[ZafSC]

Just winterized my engine today 5.0 Mercruiser. Emptied all the fresh water in the engine thru the single point system. Removed the thermostat. Then placed a big jug of antifreeze on swim platform at stern and hosed it to the muffs. Opened the jug faucet and AF starting to leak down on the muffs, showing there is enough liquid. Turned the engine on, it started to suck the AF in. It probably sucked around two gallons. Waiting to see some liquid on the exhaust, somehow, I got stressed and turned the engine off. I decided to fill the engine with AF from the thermostat opening (I should have done it before, but no big deal I thought). I completely filled the engine with AF (it took about 2.5 gallons), so thermostat opening overflowed, meaning completely full. I went back to the AF jug at the stern, opened the jug faucet, observed the AF continue, and turned the engine on.
Nothing coming from the exhaust, no water, no AF, no liquid. All the AF from jug is leaking over the muffs to the tray on the ground, but nothing coming out from the exhaust.
Other than the muffs, there is some AF is coming from the inside of propeller hole.
What is happening??

1. Did I do something wrong by running the engine empty? (i.e. no cooling liquid, whatever it takes from muffs)
2. I had run it on the muffs many times using the garden hose previously, with plenty of pressure, at the beginning of summer. From the jug, the pressure is much smaller of course. Is it a big deal?
3. Is the AF coming from inside of propeller, is it the excess liquid going into muffs? (I haven't noticed it before, didn't bother since I observed the liquid coming from exhaust all the time when running on muffs)
4. Since the engine is full of AF, any kind of testing will have to wait till next summer.
5. Has my engine winterization been successful?

Many thanks

 

[Pmt133]

I first, would not trust the single point drain to have emptied everything.

And second, would not trust sucking antifreeze via the muffs to work well.

The only way to know if it's safe would be to drain each component individually and check if the antifreeze has actually made it there and isn't diluted... and at that point you may as well have left it dry....

 

[Lou C]

Agreed I don't like that single point drain, you don't know if the block drains for sure drained, if in freshwater it might work OK but here in the salt pond, I wouldn't trust it. In fact sometimes you have to rod the drains out just to get it to drain.
Some say to remove the whole single point system but if you don't want to do that, you can disconnect the block drain hoses and rod out the actual drains, to make sure they do drain.
The only way to know if your engine is really protected is to do as I said, disconnect one hose at a time and take a sample of what comes out, and put it in the freezer to see if it freezes. I have an antifreeze refractometer, so I can easily test it.
In the future I'd do what I advised above, and if you want to use AF forget about sucking it in, it is less messy to manually fill the engine via the big hose on the front of the engine till it comes out the thermo housing. You can fill the manifolds the same way. That's what I have done for 20+ seasons.

 

[ZafSC]

I first, would not trust the single point drain to have emptied everything.

And second, would not trust sucking antifreeze via the muffs to work well.

The only way to know if it's safe would be to drain each component individually and check if the antifreeze has actually made it there and isn't diluted... and at that point you may as well have left it dry....

Each component meaning the left and right plugs on the engine? Yes I remove them and see AF coming both sides The reason I am running thru muffs is to make sure AF goes everywhere in the engine.

 

[ZafSC]

Agreed I don't like that single point drain, you don't know if the block drains for sure drained, if in freshwater it might work OK but here in the salt pond, I wouldn't trust it. In fact sometimes you have to rod the drains out just to get it to drain.
Some say to remove the whole single point system but if you don't want to do that, you can disconnect the block drain hoses and rod out the actual drains, to make sure they do drain.
The only way to know if your engine is really protected is to do as I said, disconnect one hose at a time and take a sample of what comes out, and put it in the freezer to see if it freezes. I have an antifreeze refractometer, so I can easily test it.
In the future I'd do what I advised above, and if you want to use AF forget about sucking it in, it is less messy to manually fill the engine via the big hose on the front of the engine till it comes out the thermo housing. You can fill the manifolds the same way. That's what I have done for 20+ seasons.

Ok, I only know how to fill using thermostat housing. How do I fill the manifolds with AF? Remove the manifold hoses and pour AF in?

 

[Lou C]

Yes just disconnect the hose feeding the manifold at the thermostat housing & fill each manifold. Make sure to use PG antifreeze not EG and for engine protection. I use the -100 because the -50 or -60 gets hard at a few degrees above zero. Depends on how cold it gets where you are…

 

[tpenfield]

Your engine probably can hold upwards of 5 gallons of liquid in the cooling system. If you drain the system and want to fill it with AF, it is best to fill it manually via the thermostat housing and the hoses to the exhaust manifolds.

 

[Bt Doctur]

The biggest killer to the motor is clogged block drains, You must remove the quick connects from the fitting to insure complete draining of the block.
From what you describe you never drained the motor only the manifolds and hoses.
To be safe drain everything ,pull the block drains and probe, The system can hold up to 4 gallons of water. put a bucket under the hull drain , drain it to see how much comes out . if less that 4 gallons pull the block hoses and probe

 

[ZafSC]

The biggest killer to the motor is clogged block drains, You must remove the quick connects from the fitting to insure complete draining of the block.
From what you describe you never drained the motor only the manifolds and hoses.
To be safe drain everything ,pull the block drains and probe, The system can hold up to 4 gallons of water. put a bucket under the hull drain , drain it to see how much comes out . if less that 4 gallons pull the block hoses and probe

No no, just the opposite. The two quick connects hoses go to the single drain at the front. So single drain empties all the water, that's what I did.
I am worried about the manifolds, risers and elbows. When I do the quick drain, I believe those don't get drained. How can I drain those?

 

[ZafSC]

Yes just disconnect the hose feeding the manifold at the thermostat housing & fill each manifold. Make sure to use PG antifreeze not EG and for engine protection. I use the -100 because the -50 or -60 gets hard at a few degrees above zero. Depends on how cold it gets where you are…

Sorry, I meant the riser hoses when I said manifold hoses. The manifold hoses are below the manifolds, so I cannot fill AF there. So the question becomes, if I fill in AF (from funnel, by gravity) in that yellow entry of the riser, will that AF fill the manifold as well, so that it is safe?