2004 350 mag winterization issue

[Danny C]

Ran the boat yesterday, changed the engine oil on the water (went well). Then I pulled the boat out of the water and drained the LU oil. Oil took forever (hour or two) to drain out. I had the cap off the reservoir but still slow going. When I tried to add gear oil back to the reservoir, it would not go down into the LU. It may just be real slow going and need time but it seemed to be "stuck".

Next issue was when I went to drain the cooling system. My engine has the quick drain valve and, from what I could find, two blue plugs. I opened the quick valve and pulled the bottom plug. The top plug snapped off in the thermostat. It looks like more of a vent valve since it is at the top of the system. The plug that snapped left its threads in the thermostat but the plastic plug is hollow so it is now open to atmosphere. I hooked up the engine on muffs to a bucket of antifreeze and ran it for a bit. It only took about 2-3 gallons before I could see it spitting out the LU. I then popped the large hose off the thermostat and poured antifreeze into the hose until it topped off. Question is, do you see any issues leaving the engine with the broken plug (open to atmosphere) until I can try to easy out the plug and replace next year? Any good advice for getting a broke plug out? Also, looking into the hose area there was a surprising amount of rust, especially because the outside of the engine is so clean. Should I be worried.

Any advice is appreciated, I want to make sure I do not ruin my motor on my first year winterizing it.

 

[alldodge]

I see a few problems, mainly you may not have gotten all the water out. What is your engine serial number?

 

[Bt Doctur]

To drain a drive you remove the top plug and bottom plug. To refill, you pump it in from the bottom untill it comes out the top plug, install the top plug and SLOWLY pump untill it appears in the bottle, then fill the bottle.

The quick drain system is the quickest way to a cracked block if it malfunctions. You should have seen about 4 gallons of water exit the quick drain,if not the block and or manifolds contain raw water not A/F.I recommed removing that system and install standard plugs to drain the block and manifolds

Flush and fog the motor untill it stalls
Open all drains and probe the opening to be sure it drains
Install all plugs
Remove large hose from T housing and pour 2 to 2 1/3 gallons untill it comes out the T housing, reinstall hose
Remove hoses going to the bottom of the manifolds at the T housing, pour about a 1/2 gallon in each hose,reattach hoses

 

[Danny C]

Engine Serial number is 0M67062

Ok, makes sense on the outdrive oil. Just like I used to on my outboard.

When I open the quick drain I let it sit for a long time to make sure all the water is out but there are some times when I drained it and a week later I would open again and a little water will flow out. I did crack the quick valve and saw A/F flow out.

I did not fog the motor as I did not know that was required for this motor.

I filled the large hose off the T housing but with only about 1 gallon before it flowed out of the housing.

I need to go back and fill the rest of the hoses. I poured a bunch into one of the hoses until I realized that it was on the drain side and was just dumping out the LU.

 

[alldodge]

Your serial number is missing a digit (0M and six digits) but was able to find it. You should have what is called the single point drain system. Is your thermostat housing the one on top or the bottom in link below? Also the piece that broke was it item 13 on top or item 26 on bottom?

http://www.mercruiserparts.com/bam/subassembly/31748/8093/180

Also if this is an MPI motor you shouldn't fog the motor, it will coat the sensors.

 

[Bt Doctur]

I would tend to thing the plastic wing nut is broken not the brass plug.Depending on the access to the motor try removing the quick disconnect hoses at the block. If the brass fittings are plugged up the block did not drain .

 

[Scott Danforth]

the quick drain system is problem prone. I would also suggest removing it.

 

[R055]

What everyone described above. Remove the quick drain and verify no water left. Reading your first post, I would say there is a good chance you'll be starting a "my block is cracked" thread this spring unless you can verify you got all the water out.

 

[Danny C]

Well, I am here to try to avoid the "my engine block is cracked" post in the future.

AllDodge - Yeah, the last digit is not very visible but I think it is 4. The Stat is the top on in your link and the part that broke is #13. It is a plastic blue plug. I wonder what size it is so maybe I can use a brass plug until I can get a plastic replacement. I removed the brass plugs as well in the stat housing to make sure it drained.

When I removed the bottom plug, water came out so it is not plugged up. How else can I verify water is out of the engine. I have done almost everything suggested so far.

Thanks

 

[alldodge]

Just remove the brass insert and then you can get at the blue plug. In most cases they break because they get over tightened. The O-rings should be replaced every few times. What happens is the ring looses is elasticity and requires folks to tighten them more to stop a leak. If the ring was just replaced it takes very little pressure to seal. I also replace the blue plugs ever so often just because.

The single point drain is the plug is pulled and you see water comes out. The issue is, did all of the drain hose connection fully drain, only partially drain or somewhere in between. The only way to know for sure is to remove the hoses and stick something up into the connector. You can also blow air into the hoses, one at a time to see if anything else drains out.



As others said you can replace all of them with brass plugs from the hardware store but you will need to remove the single point system

 

[Bt Doctur]

All my customers get that system removed weather they want to or not. I loop the small hoses and cap the larger manifold hoses or loop them if possable.
The connections at the manifolds are changer to just brass 90`s or the 90`s with the blue drain plug.
Cant afford to take the chance of a crack.

 

[Danny C]

Does anyone happen to know what size plug I would need to replace the blue? 1/4" NPT? 3/8" NPT?

 

[alldodge]

The thread in the block is 1/4 NPT, and if you go plugs I would suggest a brass .250 to .125 reducer (1/4 to 1/8) NPT. Reason for this is the brass plug can be replaced easy if need be. If you use the 1/4 NPT plug only and the threads mess up, then their is a bigger issue.

You can also go for the brass bushings and blue plugs
Bushing 22-860088
Blue plug 22-860088A02

 

[Danny C]

Great, Thanks for all the help.