Draining Mercruiser 5.7

[robinsbd]

I know winterization has been discussed a lot this time of year, but I just wanted to verify that I am doing the correct procedure for draining the water from my 5.7L Mercruiser engine with Alpha One Gen II drive.

I removed a total of 5 drain plugs: 2 on the block, 1 under each exhaust manifold, and 1 under the hose that carries the raw sea water from the outdrive pump to the engine thermostat housing.

I made a stiff wire from an old coat hangar and poked into all the drain holes to clear any debris.

After performing the above, I then disconnected the hose end that attaches to the engine circ pump, which allowed water to drain from the hose and the circ pump.

At this point, am I good to go as far as freeze damage prevention?

Do I need to disconnect any of the other hoses?

I am not particularly interested in using antifreeze because I am trying to follow what Bondo has said many times "Air don't freeze!!".

 

[thumpar]

The only other thing I would do is pull the hose from the thermostat housing that feeds the engine to drain the water out of there. Otherwise you have it covered.

EDIT: Looks like you got the power steering cooler but I would still pull the hose at the transom. I also crank over the motor with the lanyard off to clear out the impeller.

Just my $0.02

 

[robinsbd]

thumpar, where do you pull the hose at the transom? I don't think I have seen that part yet.

 

[robinsbd]

Another question I have is about the drain plugs. My engine had hex head bolts (3/4" heads) with gaskets. They are kinda rusty, so I purchased a set of quicksilver blue plastic plugs with O-rings. I tested them out and I found that the exhaust manifold drains leak pretty bad. The manifolds actually drained themselves after a day or so. Is there any solution for this? Thanks!!

 

[thumpar]

It could be that the rust in the manifolds is not allowing the blue plugs to fully seat.

 

[robinsbd]

Is there any reason to disconnect the hose that goes from the PS cooler to the thermostat housing? It seems like the PS cooler and hose slant downward as it goes towards the front of the boat.

 

[Scott Danforth]

pull the large hose going to the recirculating pump. that will hold a bit of water too.

 

[alldodge]

Is there any reason to disconnect the hose that goes from the PS cooler to the thermostat housing? It seems like the PS cooler and hose slant downward as it goes towards the front of the boat.

You could remove the hose but I wouldn't, there is very little water left on the rubber hose and will not damage anything.

Another question I have is about the drain plugs. My engine had hex head bolts (3/4" heads) with gaskets. They are kinda rusty, so I purchased a set of quicksilver blue plastic plugs with O-rings. I tested them out and I found that the exhaust manifold drains leak pretty bad. The manifolds actually drained themselves after a day or so. Is there any solution for this? Thanks!!

Are you putting the plastic plug directly in the manifold or did you install the brass adapter and then the plastic plug?

While there might be a slight bit of water left on one side of the seawater pump, that amount will not cause harm. I have never cranked an engine over to clear that amount of water (maybe a couple tablespoons)

Also don't see a reason to remove the hose from the pump to the transom, or the transom end. With the drive down it will drain out

 

[robinsbd]

There does not appear to be a brass adapter on the bottom of the manifolds. What I have is a small pipe with threads that faces down where the water drains out and then on the side of that is a horizontal pipe where the hose clamps onto. It sounds like I am missing some brass fittings.

Now, after reviewing all 5 drain plugs I removed, I have another concern. The first 4 plugs were for the block and manifolds. However, the 5th plug was from the bottom of a long rigid tube on the port side of the motor behind the alternator. That drain is on the stern side of the tube which looks to be a higher point vs the bow end that actually slants downward towards the belt side of the motor. I wonder if this rigid pipe is on backwards.

Also, I was under the impression that the PS cooler was on the port side of the motor, but I don't see it. I thought that the 5th plug I removed took care of the PS cooler. Where is the PS cooler, and is there a 6th plug that has to be removed?

 

[alldodge]

This is the main reason when you post a question you need to provide your serial number or at the very least the year. Suggest putting it in your signature so we all know and you don't need to remember.

You might be talking about cool fuel if you fuel injected

The blue plugs should screw into one of these adapters


Exhaust should use one of these if you have the late model manifolds

 

[robinsbd]

You are absolutely right. Sorry about that. I will create a signature with my boat and engine info.

 

[robinsbd]

I updated my sig with my boat and engine info.

The first adapter pic is what I have on my block currently, and the exhaust adapters look just like what I have under my manifolds.

 

[robinsbd]

Here is a pic of the rigid water tube from the Mercruiser manual #17. On my engine, the drain is actually on the right end of the tube instead of the left end like the picture shows. Going by this pic, I would assume someone had reversed the tube on my setup.

 

[Bondo]

Ayuh,.... That thingy in yer picture, Should be the P/S Cooler,...

 

[robinsbd]

I think it is just a straight tube section and not actually a P/S cooler.

 

[alldodge]

Here is a pic of the rigid water tube from the Mercruiser manual #17. On my engine, the drain is actually on the right end of the tube instead of the left end like the picture shows. Going by this pic, I would assume someone had reversed the tube on my setup.

That tube is used to drain the PS cooler which is on top flywheel housing. You remove the plug and it drains everything forward and to the rear of it. It is item 26 and the PS cooler is item 21

http://www.mercruiserparts.com/Show...&bdesc=STANDARD+COOLING+SYSTEM(ALPHA+ENGINES)

With it being a tad high or low could keep some water in it, you need to make the call. If its just a tad there won't be much water left so should be no harm

 

[robinsbd]

You mentioned earlier that it is not necessary to remove the water hose going to the transom. It looks like you are talking about the connection at item 12 in the diagram you posted. Can you confirm that? Thanks very much!

 

[alldodge]

You mentioned earlier that it is not necessary to remove the water hose going to the transom. It looks like you are talking about the connection at item 12 in the diagram you posted. Can you confirm that? Thanks very much!

IMO yes the water should drain out of the drive but it will be slow going and drive needs to be left full down. To verify all the water is out you could remove the hose at item 11 and lower into the bilge. This has worked fine for all Alpha's I've worked on, now haven't work on but two Gen 2 drives, so maybe someone can advise if there is a difference.

 

[robinsbd]

Hi Guys,

It's almost boating season for me. I suspect others have already begun their season.

I know we're at the opposite end of the boating season now, but I just wanted to check with you guys on the use of antifreeze or lack there of. A person at work was telling me how they always use antifreeze when they winterize and we argued about why I don't use antifreeze.

I didn't put any antifreeze at all in my engine last Fall. All I did was drain the engine by removing the 5 plugs and disconnect the main water hose that connects the thermostat housing to the engine circ pump. Can you re-confirm that this is OK and a good practice to follow?

By the way, my boat is in Illinois.

Thanks!!

 

[Bondo]

Can you re-confirm that this is OK and a good practice to follow?

Ayuh,..... Air don't freeze, No need for antifreeze in a completely drained motor,......