Will -75F antifreeze be enough for my climate?

[USA_boater]

2004 Volvo Penta 4.3GL inboard

Hoping to get away with the quick way to winterize this season so I:

- Put Stabil in the tank
- Used Camco tank system with Stabil brand -75 pink stuff and ran almost 5 full gallons though the system on the trailer (pink was running out from the exit for most of the duration all the way until the boat was shut off)
- Sprayed Stabil fogging oil in the carb for 10 seconds when Camco tank was almost empty and used it to stall the motor

I just replaced the circ pump, raw water impeller & thermostat in August and also flushed the block and picked the drains at that same time so I saw no need to open the system now as long as enough antifreeze got into the system to dilute the water to an acceptable level. This boat is stored outside in oklahoma; temp rarely goes below 20*F.

I still plan to change the lower unit fluid but that can be done soon, l I just want to know if there is any consensus based on other member's experiences that what I did will protect the motor for winterization? I had originally planned to do it the longer way but life is busy and I know MANY people just use pink stuff; I paid extra for the better stuff over the cheaper -50F generic brand.

Thanks

 

[MTboatguy]

Yes, you are protected to most things that OK can throw at you.

 

[tpenfield]

Low temperatures to only +20 F is a pretty easy winterization.

Keep in mind that just because you see the pink AF coming out of the outdrive exhaust does not mean it went through the engine. A couple of things to consider . . .

1) Most engines are set up to have some of the cooling water by-pass the engine and go straight out to the exhaust elbows. So . . . not a 5 gallons of the AF you put into the outdrive/water inlet goes through the engine.

2) The AF that actually goes into the engine block and manifolds does not displace the raw water on a 1-for-1 basis. It is a mixing process governed by the recirculating pump. So, with a typical setup as you did, you may end up with about 50% water and 50% AF still in the block and manifolds . . .

Running AF is fine, and I do it with my cooling system, but draining the block, water pump and manifolds is a more positive step to prevent freeze damage.

 

[USA_boater]

Well I warmed the boat up until the thermostat opened up with regular water before i switched over to the antifreeze. Will that mean that the block & manifolds got enough AF? Also, this boat has a water inlet inside the engine compartment that directly feeds the raw water intake hose. So I am also hoping that helped. I saw pink draining back out the lower unit water intake holes too after I turned off the motor

 

[tpenfield]

What you could do is take a sample of the liquid (presumably AF) that is in the block and another from the manifolds by draining a little bit into a few plastic bottles . . . then toss the bottles in the freezer over night, check them the next day.

 

[GA_Boater]

As soon as the thermostat was hit with the cold A/F, it slammed shut and if the temp rose enough for the stat to open before the 5 gallons was gone, you got lucky.

But how will you know? In the spring when the cracked block is making milky oil or a flooded bilge. Those kits are not reliable to use unless the block is completely drained first.

 

[bruceb58]

Pull the block drains..then pull the thermostat and pour AF in if you really want to be sure to get the AF in the block.

 

[USA_boater]

As soon as the thermostat was hit with the cold A/F, it slammed shut and if the temp rose enough for the stat to open before the 5 gallons was gone, you got lucky.

But how will you know? In the spring when the cracked block is making milky oil or a flooded bilge. Those kits are not reliable to use unless the block is completely drained first.

Well presumably, 100% AF would not cool as well as 100% water. I watched the gauge and it rose significantly more than normal after the 100% AF was feeding into the pump for a few minutes. The gauge rose above half way so I know the stat was opened while the AFZ was being taken in at least for the later half of the cycle.

Also, if I do go ahead and pour 100% AFZ into the block, can't I just pour it in the t-stat hose and it will seep past the stat without me having to remove the housing?

 

[Chris1956]

Pull the block drains and pour the straight A-F into the large recirculating hose on the waterpump. When it comes out the block drains, install the plugs and fill the block. Repeat for the manifolds, watching for AF at the manifold drains and out the exhaust ports.. Dump some down the raw water intake hose.

Throw out the camco tank...

 

[bruceb58]

Also, if I do go ahead and pour 100% AFZ into the block, can't I just pour it in the t-stat hose and it will seep past the stat without me having to remove the housing?

You can just pour it into the the large hose after you disconnect it from the thermostat. It will go directly into the block from there.

 

[jimmbo]

I just fog it, drain the block, the hoses, the manifolds and put it away. 17 seasons...

 

[H20Rat]

I just fog it, drain the block, the hoses, the manifolds and put it away. 17 seasons...

Even the fogging is pretty much optional, especially if you live in a really cold climate. Rust formation all but stops below freezing. I have generally fogged 2 strokes and never touched 4 strokes, but with that said, I've got all kinds of small 2 stroke engines (weedeaters, chainsaws, etc) that have never seen a drop of fogging oil, and they are all running fine yet.

 

[USA_boater]

Well I prefer to just drain it and be done with it...BUT, this boat was predominantly run in a high-salt content lake for 7yrs, maybe more (still considered fresh water), probably never flushed, and the stored wet and then drained at some point and sat for 5yrs un-used until I bought it. I've seen and removed a lot of corrosion and one block drain was completely plugged so water probably sat in the block for years on that side. I've replaced the stat, circ pump, dremeled out the rust on the stat housing, scraped what I could from the intake hole, flushed the block from the circ pump holes, etc. My point of using the pink stuff is to try to prevent future corrosion. If it won't help, then I'd just assume drain it and not mess with the antifreeze but you tell me if keeping air out of the block & risers will help prevent future corrosion? I will being using it in a non-salty lake now that I own it.

Considering my reasons for wanting to use the AFZ, is it worth it?

 

[USA_boater]

I called a reputable dealer today (the one my buddy uses for years) and asked their service dept's opinions. He told me the only reason they pour into the block instead of use a Camco is because it uses less AFZ and is therefore cheaper. He told me in Oklahoma, if I saw it pouring out of the exhaust, then I'm protected. He said if I was still worried, I could open a drain and test what's in the motor. I will probably at least do that; would an automotive AFZ tester (the kind with the little colored balls) work?

 

[Chris1956]

Your dealer is mistaken on the efficiency of those camco units. There is no way to assure that enough A-F gets into the block to protect it. It just might work...but it also may not. To quote a famous line "Do you feel lucky, Punk?"

 

[USA_boater]

Well I'm not in North Dakota...even if 50% AFZ and 50% water is in the block, I'd be protected down to -21F by my math...that is if I split the diff of -75 and 32*F...is that the right way to calculate it?

 

[harringtondav]

My two cents is to second all those above who say to pull the plugs, lower circulating pump hose, PS cooler inlet, and get all of the water out. This takes 15 minutes. A teeny fraction of the time it takes to R&R a cracked engine.

My '96 4.3 is a Merc., but I bet the draining is the same. My 4.3 has a hot water outlet in the front of the intake manifold for a cabin heater. You can pull the pipe plug, and funnel in the antifreeze until it splatters on the driveway at the stern.

 

[Lou C]

I responded to your thread on the hull truth asking the same question, and I am in agreement with all the people here who say, you really should at least take a sample from your block drains and put that in the freezer. This will remove all doubt as to whether or not that AF/water mix is strong enough. When in doubt drain it all because you will cost yourself a LOT OF MONEY if you freeze that engine, for no good reason, other than taking a short cut, that no motor manufacturer ever advised its customers to do.....
Having said that....
has anyone ever seen Mercrusier, Volvo Penta or OMC instruct you to winterize a raw water cooled inboard with a winterizing tank, in one of their owners or shop manuals? No one has because they don't advise doing it that way, due to the way raw water cooling works, it is simply too risky. You THINK the 'stat is open far enough to let all the raw water exit the block but you don't KNOW that. Marine shops that use this method, re-circulate the AF to keep the stat open by keeping the AF hot. The only safe way to do it, is to drain your engine manually, poke the holes, and then back full through the big hose at the front and the manifold feed holes.
Also, that -75 is a pipe burst temp, it is not a freeze temp. PG antifreeze will start to solidify at a much higher temp than the bust temp which is how they are advertised. And personally if I am putting AF in my cast iron engine, I surely want it to stay liquid all winter no matter how cold it gets. So I use either -100 marine antifreeze (freeze temp is -45*F), or mix up a 50/50 mix of Sierra PG engine antifreeze which won't freeze till -26 F. Where I am the coldest we see is 0* F so the Sierra is fine and a cheaper alternative to the -100.


Ps tried that the first year. Then checked the drains. What came out was dirty rusty water!
Took the winterizing tank and turned it into a flusher for my drum trailer brakes, powered by a 12V live well pump.

 

[Lou C]

I called a reputable dealer today (the one my buddy uses for years) and asked their service dept's opinions. He told me the only reason they pour into the block instead of use a Camco is because it uses less AFZ and is therefore cheaper. He told me in Oklahoma, if I saw it pouring out of the exhaust, then I'm protected. He said if I was still worried, I could open a drain and test what's in the motor. I will probably at least do that; would an automotive AFZ tester (the kind with the little colored balls) work?

Honestly the level of ignorance and incompetence out there is disappointing. This from a dealer? He does not understand how raw water cooling works. If your stat does not open or does open all the way, that AF just went through your exhaust system, and you risk busting open a perfectly good engine!

I'd change probably do that, to definitely check the freeze strength (remember, its PG antifreeze so a EG hydrometer will not work on it, different specific gravities). Either get the right tool, or put it in your freezer set at zero, if that's the coldest you get.

EG=ethylene glycol (automotive antifreeze, toxic)
PG=propylene glycol (RV type antifreeze, Sierra brand can be used in vehicles or for winterizing, non toxic)

EG has higher boil and lower freeze temps than the same % of PG antifreeze.

 

[jkust]

I wonder if the difference is that you were talking to a counter guy versus a knowledgable tech? I was dropping my boat off a couple weeks back at my marina at the service counter and the phone was ringing off the hook with people asking technical questions of the counter guys who's advice was all questionable but vague at the same time. The techs were all working at 120% of capacity and no way were they in a position to be on the phone.

End of the day, it's a lazy way to winterize if you don't pull the draincocks or the plugs and properly facilitate full draining in the newer I/O's. There is a risk with every choice and the risk here has been covered well so far.