mercruiser 3.0 freeze plug blew out

[Bondo]

Re: mercruiser 3.0 freeze plug blew out

if there was ever a winter to prove once and for all to just drain the darn thing and leave it empty. this is it...... I read my manual, researched how others winterize,, I chose to listen to elders,, ie- Bondo's "air dont freeze".. made sense to me.. that's what I did, drained it, used compressor to blow it out and left her there covered up,,, will report this spring how that worked out...

Heeeeeey,.... Who are you callin' Old,..??

I'm just a Young pup,.... celebrated the 29th anniversary of my 29th birthday, just last June,.... :lol:

 

[Starcraft5834]

Re: mercruiser 3.0 freeze plug blew out

my bad......... anyone who's posted 51,818 times....... I thoughts been around the block,, more than me . what u down to in snow pile up there? 5 ft?

 

[wrench 3]

Re: mercruiser 3.0 freeze plug blew out

I used to go old school and leave the drain plugs out over the winter but had to drill and tap a couple of the holes oversize, because the threads rusted out of the block and manifold. So now I put them back in after draining everything.
But if you have the taps with the removable spigots, it would be OK to leave the spigots out.

 

[alldodge]

Re: mercruiser 3.0 freeze plug blew out

Heeeeeey,.... Who are you callin' Old,..??

I'm just a Young pup,.... celebrated the 29th anniversary of my 29th birthday, just last June,.... :lol:

:laugh: :hail:

 

[Starcraft5834]

Re: mercruiser 3.0 freeze plug blew out

I used to go old school and leave the drain plugs out over the winter but had to drill and tap a couple of the holes oversize, because the threads rusted out of the block and manifold. So now I put them back in after draining everything.
But if you have the taps with the removable spigots, it would be OK to leave the spigots out.

I drained, blew out, and screwed plugs back in.. hope I did not screw anything up...

 

[cdoo1972]

Re: mercruiser 3.0 freeze plug blew out

That's the way I was going to winterize it originally. That how the previous owner had done it because I had to reinstall them when I got it. Friends on my lake were the ones that convinced me to do it the way I did. Next year I'm taking your advise and its getting completely drained. Well parts are ordered And weather permitting get it back together this weekend. I'll let you know the outcome

 

[old islander]

Re: mercruiser 3.0 freeze plug blew out

Just my 2cents here. I'm almost as old as Bondo, had boats most of my life. I just drain the block, leave the plug out and the petcocks open and call it a day. Never had a frozen block in 12 or so boats or 42 years.

 

[JimS123]

Re: mercruiser 3.0 freeze plug blew out

The trouble with just pumping the antifreeze through is that you warm up the engine to open the thermostat, but then the cold antifreeze hits it and it closes before much gets in.

The engine is run on cold city water from the tap thru the muffs. The antifreeze is in gallon jugs sitting in the warm house. The anti-freeze is warmer than the water used to warm up the engine to make the Tstat open.

 

[Scott Danforth]

Re: mercruiser 3.0 freeze plug blew out

That's the way I was going to winterize it originally. That how the previous owner had done it because I had to reinstall them when I got it. Friends on my lake were the ones that convinced me to do it the way I did. Next year I'm taking your advise and its getting completely drained. Well parts are ordered And weather permitting get it back together this weekend. I'll let you know the outcome

If your friends winterized in the same manor, take solas in the fact that they probably will have problems this spring.

 

[havoc_squad]

Re: mercruiser 3.0 freeze plug blew out

-5 wouldn't do much good around here this winter. We've hit -32F so far and we're "down south" as far as Canada is concerned. That's why I always put a little antifreeze in through the hoses to the oil coolers, manifolds, circulating pump, etc. Just for peace of mind.

-5 F was worst case scenario guess for the RV/marine antifreeze with any remaining antifreeze with water in it.

The reason for the extra step I mentioned previously of draining everything twice (one to rid of the water, the other to rid of the RV/marine antifreeze, was to ensure items like the water pump assembly and the outdrive didn't somehow have a large pocket of water that wouldn't drain.

If something bad is gonna happen or something go wrong, it's gonna do it when I'm involved. Thus the $20 anti-freeze insurance.

 

[Bondo]

Re: mercruiser 3.0 freeze plug blew out

The engine is run on cold city water from the tap thru the muffs. The antifreeze is in gallon jugs sitting in the warm house. The anti-freeze is warmer than the water used to warm up the engine to make the Tstat open.

Ayuh,... Which doesn't matter is any way what so ever,...

If ya Don't Drain 1st, yer chances are Still 50/ 50, at Best,...

 

[UncleWillie]

Re: mercruiser 3.0 freeze plug blew out

The engine is run on cold city water from the tap thru the muffs. The antifreeze is in gallon jugs sitting in the warm house. The anti-freeze is warmer than the water used to warm up the engine to make the Tstat open.

Once the block fills with water, it just circulates between the block and the water pump until the thermostat opens. The thermostat dumps some of the block water out the exhaust and the same amount of of cold water mixes with the hot water in the block to hold the temperature at the thermostats opening temperature.

One you drain the block and refill it with antifreeze that is well below 100F, the T-Stat closes again until the block heats up.
So pre heating the block is really an exercise in futility.

Here is my CYA method that is overkill, but makes me sleep well at -20F.

1. Remove the Thermostat from the engine. (Now is a good time to test it!)
2. Drain the block of all the water.
3. Run 6 gallons of -50F Antifreeze through the idling engine.
4. Drain the block of all the antifreeze. (Save it for next year!) *
Air Doesn't Freeze! The Antifreeze remaining in the low spots wont either.

* Placing a kiddie pool under the engine will help in recovering at least 5 gallons.
Add one gallon of -200F Antifreeze to the mix next year to improve the strength.

 

[tpenfield]

Re: mercruiser 3.0 freeze plug blew out

One of the misconceptions about the "anti-freeze only" (no draining before or after) approach to winterization is that the AF does a 1-for-1 'swap' with the water that is in the engine. It does not. The exchange of AF for water is more of a diluting process. Therefore, running 4-5 gallons of antifreeze through the engine may only result in a 50/50 mix of AF and water inside the engine, giving substantially less protection.

Additionally, with many I/O engines, a portion of the incoming water (or AF) routes directly to the risers for exhaust cooling, bypassing the engine block altogether. So, if you run 5 gallons in to the cooling system, you might be getting only 3 gallons to the block and manifolds.

 

[Bullrider]

Re: mercruiser 3.0 freeze plug blew out

One of the misconceptions about the "anti-freeze only" (no draining before or after) approach to winterization is that the AF does a 1-for-1 'swap' with the water that is in the engine. It does not. The exchange of AF for water is more of a diluting process. Therefore, running 4-5 gallons of antifreeze through the engine may only result in a 50/50 mix of AF and water inside the engine, giving substantially less protection.

Additionally, with many I/O engines, a portion of the incoming water (or AF) routes directly to the risers for exhaust cooling, bypassing the engine block altogether. So, if you run 5 gallons in to the cooling system, you might be getting only 3 gallons to the block and manifolds.

I live in the Pacific Northwest. It gets down to the 20s here on occasion and in the teens not as often. What temperature at length is time for concern of cracking? After reading these posts I understand I have not winterized my engine properly and surely dodged a bullet. I guess if I have worries the cold will win I will roll her into the shop for the few days of cold we get from time to time. (We have boating activities through the winter here)

 

[Bondo]

Re: mercruiser 3.0 freeze plug blew out

I live in the Pacific Northwest. It gets down to the 20s here on occasion and in the teens not as often. What temperature at length is time for concern of cracking? After reading these posts I understand I have not winterized my engine properly and surely dodged a bullet. I guess if I have worries the cold will win I will roll her into the shop for the few days of cold we get from time to time. (We have boating activities through the winter here)

Ayuh,.... 1 of my Mentors, God Bless 'im, always said 6 hours at 26? is a Cracked block,....

But,.... I've never tested his theory,....

 

[wrench 3]

Re: mercruiser 3.0 freeze plug blew out

-5 F was worst case scenario guess for the RV/marine antifreeze with any remaining antifreeze with water in it.

The reason for the extra step I mentioned previously of draining everything twice (one to rid of the water, the other to rid of the RV/marine antifreeze, was to ensure items like the water pump assembly and the outdrive didn't somehow have a large pocket of water that wouldn't drain.

If something bad is gonna happen or something go wrong, it's gonna do it when I'm involved. Thus the $20 anti-freeze insurance.

Originally Posted by wrench 3
-5 wouldn't do much good around here this winter. We've hit -32F so far and we're "down south" as far as Canada is concerned. That's why I always put a little antifreeze in through the hoses to the oil coolers, manifolds, circulating pump, etc. Just for peace of mind.

It was meant to be a comment on the weather. Not your winterizing. Extra caution is always a good idea.

 

[fishrdan]

Re: mercruiser 3.0 freeze plug blew out

(We have boating activities through the winter here)

Same here,,, During the winter I just drain everything at the launch ramp, after loading up the boat and readying everything for the trip home. Only takes a couple of minutes.

 

[cdoo1972]

Re: mercruiser 3.0 freeze plug blew out

So far I have all the surfaces and hose connections cleaned up. Parts will be in tomorrow.Made up a pressure tester and filled the manifold with acetone as suggested in another forum to check for cracks. Its been full to 2 hrs now and no leaks.
Could I pour acetone down the coolant journals in the back of the block to check for internal leaks since the head is off? Or should I just wait and reassemble everything and pressure test it?

 

[Lou C]

Re: mercruiser 3.0 freeze plug blew out

I don't think I'd put acetone in the block because it can affect seals and hoses. The only sure test is to run it under load.
The only safe way to use AF is to manually drain, poke all holes, and then manually fill with -100 AF. Just like it says in my '88 OMC shop manual and current Merc manuals. I don't know why people think they know more than engineers.

 

[thumpar]

Re: mercruiser 3.0 freeze plug blew out

Because air doesn't freeze until around -350F and it is free.