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Winterizing closed cooled 5.0

T

Trav89

New member
Hi,
I am just trying to get the best possible advice for properly winterizing my closed cooled 5.0 (half system block only) Merc. Can I just pull drain plugs on manifolds and run 4 gallons of antifreeze through muffs with a jug placed on swim platform? Will that be enough to push any fresh water out the heat exchanger and replace it with antifreeze? Do I have to pull end caps off first? I can’t locate a drain plug on this heat exchanger. Also, should I pull the plugs again afterwards and store it dry?
 
Hey sorry it’s 0L652858.
2000 Mercruiser 5.0 2 bbl carb. I initially ran it on muffs until it came out the exhaust (about 4 gallons) and fogged. I mistakenly drained the exhaust manifolds by pulling the plugs and removed the lower hose to drain the antifreeze. Now I’m regretting and thinking I should have left it in. Should I pull hoses off the top and fill the manifolds up using a funnel and pour in method. When I removed the lower hoses from manifolds, antifreeze rushed out. Would this have drained anything from the heat exchanger or just the manifolds and hoses?
Thanks
 
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I have PM'ed thread starter to get answers to him

Said
Pumping AF through before emptying all water is bad because it will mix with the water and dilute the protection. If your system is empty then it's protected because air doesn't freeze. Many will add AF after draining for added protection to the metal but in fresh water it's not much of an issue. Do probe the drain homes with a wire or long screw to make sure there isn't a piece of crud keeping the rest of the water to come out
 
Thanks guys for this. So if I can’t find an actual drain plug on heat exchanger, can I pull the hose off that feeds the manifolds to drain? Or do I actually need to remove the heat exchanger end caps? im just worried the 4 gallons I pumped through mixed and diluted the heat exchanger and now I want to drain it to be safe.
 
The HE raw water goes around the outside of the unit, meaning all raw water drains automatically when manifolds are drained.

You drained them once so your good, but don't remember the screw or wire up the manifold drain plugs
 
I agree with Alldodge in post #7.

There is 1 thing to consider however & that is IF sedement (typically sand) has settled in low spots, it will remain wet. Sometimes enough to cause a crack.

So, I drain the system then pour antifreeze in until it flows out all the open hoses/petcocks/drain plugs. After is slows to a trickle, then reinstall any hoses & close any petcocks/plugs as applicable. This will saturate any sedement with antifreeze.

And, don't forget in the spring, after starting the engine for the 1st time open the motor cover & check for any leaks while it idles.
 
Trav89 said:
Thanks guys for this. So if I can’t find an actual drain plug on heat exchanger, can I pull the hose off that feeds the manifolds to drain? Or do I actually need to remove the heat exchanger end caps? im just worried the 4 gallons I pumped through mixed and diluted the heat exchanger and now I want to drain it to be safe.
Click to expand...

I have a diagram i will upload tomorrow with some verbage but you are approaching this ALL WRONG.


You are all wrong in your thoughts and methods and ideas and understanding.

Stop trying to suggest and start asking how.

You will mess up and it might cost you thousands of dollars.
 
kghost said:
I have a diagram i will upload tomorrow with some verbage but you are approaching this ALL WRONG.


You are all wrong in your thoughts and methods and ideas and understanding.

Stop trying to suggest and start asking how.

You will mess up and it might cost you thousands of dollars.
Click to expand...
Ok, thanks for the heads up. I appreciate the help and feedback.
So initially I removed the manifold plugs, stuck a wire and poked around draining both manifolds. Then I used a winterizing kit tank with 5 gallons on antifreeze connected to the muffs and ran about 4 or so gallons through while fogging.
Sounds like that should take care of protecting the raw water system? Please feel free to let me know if that’s wrong. I do have the schematic from the service manual regarding the raw water loop, I think i was just overthinking the heat exchanger draining part of the system.

Again thanks to everyone for the advice. First year winterizing the boat myself and I tend to overthink things and want to do it professionally.
 
First, I have run your Serial number and it shows a closed cooling system that only is closed for the engine block and the heat exchanger, on engine water circulation pump and thermostat. Not the exhaust manifolds. It shows only ONE hose going to the bottom of the exhaust manifolds.

Is this what your system has? Please reply with an answer and if it is not like the link shows, please explain why not and what you have.


So if your system matches what is shown in the link, there are only a few things for you to do to winterize this.

1. Remove hoses at bottom of the two exhaust manifolds. this will drain raw water out of the manifolds and the elbows attached to them.

2. The heat exchanger should have a drain screw to drain the raw water out of it. (it may have two), you will need to identify which one is RAW water and remove it to drain the raw water. If there are no drain plug(s) then your first post asking about running antifreeze thru the system will work? Yes this will work to push the Raw water out of the on engine water pump impeller housing and the heat exchanger. Pulling the hose off the heat exchanger will also drain it. The diagram from the link shows ONE incoming raw water hose to the heat exchanger and two output raw water hoses from the heat exchanger to the exhaust manifolds. It may drain out when you remove the hoses from the bottom of the manifolds but it would be best to confirm by pulling the Raw water hose of the heat exchanger.

3. You dont say if your outdrive is a Alpha or a Bravo???? Which is it?

The Bravo uses a on engine water pump impeller as shown in the diagram in the link. Please answer this question about drive type. If you have a Bravo drive and a on engine impeller system, This needs to be winterized as this is how the RAW water is drawn into the system.

So please answer my questions and if possible upload a picture of your engine showing the hose routing and thermostat housing.
 
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AllDodge said:
Look forward to seeing the all wrong part
Click to expand...
I was not referring to you or anyone responding to this post.

It was meant for the OP. As usual. NO full details of what he has. Only a serial number but no description of boat, if it is a I/O and what Drive or Inboard...................
 
kghost said:
First, I have run your Serial number and it shows a closed cooling system that only is closed for the engine block and the heat exchanger, on engine water circulation pump and thermostat. Not the exhaust manifolds. It shows only ONE hose going to the bottom of the exhaust manifolds.

Is this what your system has? Please reply with an answer and if it is not like the link shows, please explain why not and what you have.


So if your system matches what is shown in the link, there are only a few things for you to do to winterize this.

1. Remove hoses at bottom of the two exhaust manifolds. this will drain raw water out of the manifolds and the elbows attached to them.

2. The heat exchanger should have a drain screw to drain the raw water out of it. (it may have two), you will need to identify which one is RAW water and remove it to drain the raw water. If there are no drain plug(s) then your first post asking about running antifreeze thru the system will work? Yes this will work to push the Raw water out of the on engine water pump impeller housing and the heat exchanger. Pulling the hose off the heat exchanger will also drain it. The diagram from the link shows ONE incoming raw water hose to the heat exchanger and two output raw water hoses from the heat exchanger to the exhaust manifolds. It may drain out when you remove the hoses from the bottom of the manifolds but it would be best to confirm by pulling the Raw water hose of the heat exchanger.

3. You dont say if your outdrive is a Alpha or a Bravo???? Which is it?

The Bravo uses a on engine water pump impeller as shown in the diagram in the link. Please answer this question about drive type. If you have a Bravo drive and a on engine impeller system, This needs to be winterized as this is how the RAW water is drawn into the system.

So please answer my questions and if possible upload a picture of your engine showing the hose routing and thermostat housing.
Click to expand...
Thanks Kghost for the response. It is a 2000 Bayliner 2052 LX Capri, with the Mercruiser 5.0
2 bbl carb, alpha gen 2.
As stated before, this will be first year winterizing myself, as I am trying to learn and do my own maintenance and learn the ins and outs of the engine and drive. It is the correct engine that you posted, by the looks of the diagram. It has one raw water inlet, coming from the drive through power steering cooler, into the Heat exchanger, and then two hoses exiting to bottom of the manifolds. And of course the closed loop coolant circuit that runs into the water circulation pump/thermostat etc.
There is actually a capped hose on the bottom right of the heat exchanger that I have not touched, it’s a snubbed hose cap extends about 1.5 inches down with a hose clamp. Could this possibly be a drain port?

I guess really what I’m asking is if I should keep the raw water circuit full of antifreeze (if it’s worthwhile for protecting riser gaskets, corrosion etc) or keep it empty for the winter. I boat in salt water and I’m in the Pacific Northwest so mild winters but wet and humid. I did thoroughly flush with salt away also before draining everything and pulling antifreeze in through the muffs.

I can confirm the system is empty now, I pulled raw water inlet hose off heat exchanger to verify. Tried uploading a picture but wasn’t able to.
Thanks again for the reply and advice.
 
I guess really what I’m asking is if I should keep the raw water circuit full of antifreeze (if it’s worthwhile for protecting riser gaskets, corrosion etc) or keep it empty for the winter. I boat in salt water and I’m in the Pacific Northwest so mild winters but wet and humid. I did thoroughly flush with salt away also before draining everything and pulling antifreeze in through the muffs.
Click to expand...
For fresh water boaters use AF or not is a opinion answer, but since you boat in salt I would keep it full of AF to help slow down and protect the internals.
 
Trav89 said:
Thanks Kghost for the response. It is a 2000 Bayliner 2052 LX Capri, with the Mercruiser 5.0
2 bbl carb, alpha gen 2.
As stated before, this will be first year winterizing myself, as I am trying to learn and do my own maintenance and learn the ins and outs of the engine and drive. It is the correct engine that you posted, by the looks of the diagram. It has one raw water inlet, coming from the drive through power steering cooler, into the Heat exchanger, and then two hoses exiting to bottom of the manifolds. And of course the closed loop coolant circuit that runs into the water circulation pump/thermostat etc.
There is actually a capped hose on the bottom right of the heat exchanger that I have not touched, it’s a snubbed hose cap extends about 1.5 inches down with a hose clamp. Could this possibly be a drain port?

I guess really what I’m asking is if I should keep the raw water circuit full of antifreeze (if it’s worthwhile for protecting riser gaskets, corrosion etc) or keep it empty for the winter. I boat in salt water and I’m in the Pacific Northwest so mild winters but wet and humid. I did thoroughly flush with salt away also before draining everything and pulling antifreeze in through the muffs.

I can confirm the system is empty now, I pulled raw water inlet hose off heat exchanger to verify. Tried uploading a picture but wasn’t able to.
Thanks again for the reply and advice.
Click to expand...

OK, Because you have a alpha outdrive the image shown in the link is only partially accurate. You do NOT have an on engine water pump impeller.
The impeller is in the outdrive.

So, If you first drain the exhaust Manifolds, then the Raw water sides of heat exchanger and then you use a external source with antifreeze to be drawn in thru the muffs used on the outdrive, This will fill and push any remaining Raw water out of the Raw water side of your cooling system.

Not sure exactly how much antifreeze, but I would say 2-4 gallons so if you use a 5 gallon bucket, drill a hole near bottom and install a barb fitting and then attach a garden hose from bucket to muffs, this would be a good way. Best to have the bucket higher than the outdrive muff location.

Note: It is important to check the Antifreeze that is in the closed cooling side of your system every so often. Use an antifreeze hydrometer (a bulb-and-pipette tester with a floating indicator) to determine of the antifreeze is still in good shape.
 
FWIW, the hydrometer will on assess the concentration of antifreeze in the coolant mixture...you should also measure the pH, at a minimum.
 
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