Winter Antifreeze methods for 5.0MPI

[RaceCarRich]

Topic has been sort of beat to death and I've done a lot of reading and searching here over the years. Even so, it's an important enough decision with VERY severe consequences that I have to ask for opinions. I know thousands of people do either of my outlined methods each year and that I'm probably over-thinking this but I don't want to learn the hard way. I'm a well maintained 5.0L MPI/Bravo3 raw water cooled with what I believe is called the 3 point drain system.

I know conventional wisdom is air doesn't freeze (I get it, that's how I used to winterize my old 3.0L) and that the block drains often clog (I also get that as I removed the single point drain on my old 3.0L and would poke the clogged block drain). Let's assume that I can't get to the block drains on this boat (at least without removing manifolds at minimum). Would you:


A) Pull the 3 drain plugs and one vent plug to drain water then reinstall. Next get one of those kits that sits on the swim platform and feeds antifreeze through the muffs until the liquid exiting the drive while running is pink? Even then I would continue to run more gallons through just to be certain and dilute any possibly remaining water.

or

B) Pull the 3 drain plugs and one vent plug to drain water. Next pull the big hose off thermostat housing and fill with a little antifreeze until I witness it start coming out the drain plug holes (just to confirm it is getting through the block drains). I would then replace the drain plugs and fill the big hose until pink starts coming out the thermostat housing. I would probably continue with another gallon just to be certain and dilute any possibly remaining water. I would reinstall the large hose and pull the two smaller hoses going to the manifolds. Fill each small hose (again perhaps overfill) and then reinstall the small hoses.

In either case I would be on the lookout for danger signs like not much water draining when the blue plugs are pulled.

or

C) Absolutely refuse to use either A or B method and would rather pull the motor if necessary.


Thanks for your opinions. I know many of you must be sick of giving winterizing advise multiple times each year although I did search and read which is how I even came up with these two plans of attack. The rest of winterizing I got down pat (changing engine and drive oils, changing fuel filters, sink lines, etc.) its just the engine freeze protection on this setup that I've never done before.

 

[Scott Danforth]

I would remove the 3-point drain system and install traditional block plugs myself

especially after seeing how plugged the 1-point and 3-point systems become

 

[RaceCarRich]

So your going with “C”.

Problem is that I can’t get to the damn block drain holes. That’s pretty much why they invented these silly drain systems. I think I could blow air up the two small hoses that go from each side of the block to the hard tube down near the balancer.

Thanks.

 

[alldodge]

There is no way I would pull the motor to drain the block

Being your unable to get to the drain hoses attached to the block, so removing them will not help. Use the drain system and drain everything. Then pour AF into block from thermostat and redrain

Could also
You should be able to see which hoses come from the block. Remove those hoses and blow air up thru them. Put plugs on those hoses and remove the others to regular drain system Then each time used to drain , use air up the hoses to ensure they are clear

 

[Scott Danforth]

Those hoses and that spider tube are probably plugged solid. I have never found one that wasnt mostly plugger or completely plugged

 

[Rick Stephens]

Might be able to cut off the block drain hoses and put simple fittings on the end with a plug. Then run a piece of wire up them the right length to probe the drain holes. I wouldn't tolerate a 3 point. Dynamite, plastique, jellied gasoline.....good insurance.....

 

[RaceCarRich]

Hmmm.. thinking about it, if I get to the two hoses that come from the block sides to the tube near balancer, I could pinch them closed, disconnect them from tube, then unpinch and watch both drain for volume and sameness. And then add some antifreeze to the big thermostat housing hose and watch to make sure antifreeze starts to drain from each of those block hoses before reattaching or putting a plug on each for next year. Am I thinking correctly?

So just filling the smaller hoses going from the thermostat housing to the manifolds is fairly safe with no workarounds needed for manifolds?

This is enough to drive a boater to an outboard!?!

I wish I knew how my now retired mechanic used to do it.

Thanks to all.

 

[Stinnett21]

Just curious, why can't you reach the drains? You might have to take some of your boat apart to gain access. I have the typical bucket seat sun lounger setup with the panels on each side of the engine. The panels have cutouts that provide minimal access but I remove the entire panels before winterization which helps greatly plus gives complete access for other off season maintenance. I have a 5.0 MPI also and this gives me access to pull the quick disconnects on each side of the block. Don't mean to insult with this question, just want to better understand.

 

[RaceCarRich]

Nothing is removable on the sides. I’ll try to check it out more with my mirror and maybe get access pics next time I’m at marina. Starboard side is flanked with walk through steps (non removable fiberglass). Port side has a non-removable fiberglass divider (horizontal not vertical) between the engine cover cushion and the next cushion.

Why can’t I reach them? Maybe it’s my size, skill or flexibility relative to access provided. I’ll have to check again but I truly can’t even see them. Are they just elbows screwed in the block to the hoses? Do I just pull the hose and probe or do I unscrew them?

The frustrating thing is that all over the Internet are people claiming to use Method A or B successfully year after year but over here at iBoats those methods are a death sentence. And, yes, it’s evident to me that folks here at iBoats are more knowledgeable. I’ve had those block drain holes clog on my old race engines so I know it’s a reality.

Wouldn’t putting 10 gallons of antifreeze through the muffs (Method A) be enough to displace most water and still have an acceptable ratio?

Appreciate the guidance.

 

[alldodge]

If all the water is removed then method A or B will work. I don't like A because this requires the water pump to run and it can run dry for a bit before the AF gets to it. This is why I mentioned B before

Being your unable to get to the drain hoses attached to the block, so removing them will not help. Use the drain system and drain everything. Then pour AF into block from thermostat and redrain

The thing is IF all the water comes out

 

[Scott Danforth]

Hmmm.. thinking about it, if I get to the two hoses that come from the block sides to the tube near balancer, I could pinch them closed, disconnect them from tube, then unpinch and watch both drain for volume and sameness. And then add some antifreeze to the big thermostat housing hose and watch to make sure antifreeze starts to drain from each of those block hoses before reattaching or putting a plug on each for next year. Am I thinking correctly?

So just filling the smaller hoses going from the thermostat housing to the manifolds is fairly safe with no workarounds needed for manifolds?

This is enough to drive a boater to an outboard!?!

I wish I knew how my now retired mechanic used to do it.

Thanks to all.

you wouldnt need to pinch these.... those two lines will be plugged solid

 

[RaceCarRich]

If all the water is removed then method A or B will work. I don't like A because this requires the water pump to run and it can run dry for a bit before the AF gets to it.

Have you seen the kits where AF reservoir tees into garden hose going to muffs? Open AF valve then close water valve so it never runs dry.

 

[Lou C]

the problem with doing the suck AF up the drive method....if you don't drain first...is...you start the engine...it warms up...but its all full of raw water...you turn on the valve to switch from water to AF, and see AF at the exhaust ports on the transom mount and think all is OK? Well all that means is the AF is going out the exhaust system. The engine thermostat acts as a mixing valve and allows water out of the engine to maintain a certain temp. So if the engine barely reaches the set point of the stat, it may only open a little and the engine may still be mostly full of raw water whereas the exhaust is full of AF.
This is why it can be a death sentence! The way marinas make this work is to re-circulate the AF to keep it hot enough to make the stat open and stay open. It can be done by a DIYer but is only safe if you open a drain and put a sample of what comes out in the freezer. If it does not freeze at like zero its probably fine.

So....if you can't get to your drains, then how would you change a starter, which is a common repair? Pull the engine? How about the steering actuator on the transom mount? Power steering cooler?
I would take that boat to a good fiberglass shop and say, make this stuff removable for me and correct the horrible mistakes in design that the less than intelligent designers made on that boat. There is a way to do it, someone on the Bayliner board did something similar. Either that or certain jobs will never get done, or cost way too much.
Anything in my boat in the way of maintenance over the years was either removed for good or made removable.

What should be done:
get rid of the 3 point, one point whatever idiotic drain system Merc came up with because they didn't put closed cooling on all their inboards as they SHOULD be.
use metal drain plugs not the stupid Merc plastic that breaks off in the engine!
probe all the holes
put gasket sealer on the drain plug threads, they won't ever corrode that way
back fill through the large hose top end, till you see AF spurt out the thermo housing no need to remove thermostat
back fill manifolds through the hoses till no tox AF runs out the exhaust.
back fill raw water intake hose from the transom mount with the drive down till AF runs out the water intakes on the drive

Doing it this way close to 20 years never ever a problem. You must have access to your drains, starter, exhaust system, to not is unacceptable. Who built this boat?

 

[RaceCarRich]

Since the starter isn’t visible with the manifold on (really I tried to see it) I asked my now retired mechanic how you would possibly remove the starter. He mentioned two guys who were well acquainted with each other could do it with one guy holding on the socket with another guy laying over turning the end of the ratchet.

I’ll have to take another look. Hopefully I can see what I’m dealing with using a mirror and then maybe reach by feel only if my arm can fit in. We all know repairs cost too much and this is one reason why. Pisses me (and you obviously) off that Mercruiser designed a defective drain system. That and the online videos of people doing their 10 minute Antifreeze winterizing like it’s a piece of cake. Pull four blue plugs. Pour antifreeze here, here, and here. Done.

I ordered the Hardin Marine stainless steel plugs this morning actually!

When you say backfill the raw water intake hose, I’m assuming the stiff red hose that goes to sea water pump (Bravo3). My driveway is sloped so the transom will be downhill all winter. I’ll lower the nose of the trailer down on a floor jack to get everything level when I do all the work. Where would I fill it from exactly?

 

[Scott Danforth]

Pisses me (and you obviously) off that Mercruiser designed a defective drain system. That and the online videos of people doing their 10 minute Antifreeze winterizing like it’s a piece of cake. Pull four blue plugs. Pour antifreeze here, here, and here. Done.

they did it for the marketing aspect. it only has to work past the warranty period. that little video sold lots of boats with Mercruiser motors

I ordered the Hardin Marine stainless steel plugs this morning actually!

In a pinch, you can use a 1/2-13 bolt 5/8" long and an o-ring. if you can only find a 3/4" long bolt, use two washers

When you say backfill the raw water intake hose, I’m assuming the stiff red hose that goes to sea water pump (Bravo3). My driveway is sloped so the transom will be downhill all winter. I’ll lower the nose of the trailer down on a floor jack to get everything level when I do all the work. Where would I fill it from exactly?

at the thermostat housing

 

[RaceCarRich]

I wasn’t referring to a Mercruiser sales video although I bet that must be entertaining. I was referring to all the DIYers making videos of how they do it. None seem to be accessing block drains or struggling with their methods. All seem easy-peasy.

I’ve attached a few goodies as a reference to what I’m referring to.

 

[RaceCarRich]

[No message]

 

[RaceCarRich]

[No message]

 

[RaceCarRich]

Not exactly a DIYer (Powerboat TV), antifreeze starts at 4 minute mark on this 4:26 video.

 

[alldodge]

I did not watch all vids start to finish, just zipped until they got into next section

There is no way I would follow post 18 for 2 main reasons. A EFI motor is not fogged with oil, this will mess up the sensors. The block was not drained prior to adding AF