Flushing raw water with coolant

[Rob H 37]

When flushing the raw water system with engine coolant, as part of the winterising process do you have to use some kind of marine coolant or does standard engine coolant from Hal fords work just as well>

Can the same be said for the fresh water cooling systems also?

By the way the engines are Volvo KAD44’s if that’s important.

Ta

 

[spannerman]

Take off the water hose just in front of the drive centre section and fit a 3/4" dia hose into it and tighten the clamp. You have now extended the water intake so you can place it into a container which you run a hose into so it fill faster than the motor uses it. Run the engine up to flush the raw water system, checking off course that you have water exiting the exhaust soon after starting the motor. After 10 mins pull the extended hose out of the container and put it into a 5 litre can of 50% mix anti freeze, you will need two cans ready for this and any decent antifreeze will do.
Have someone ready to turn off the motor when you empty the 2nd can, you should by now see antifreeze coming out off the exhaust. Refit the hose to the drive and have a coffee, you have now winterised your engine the way we in the dealership do it, in Norway where its much colder!!
regards Steve

 

[Rob H 37]

Thanks for that Steve

I was more interested to learn if the type of antifreez I use is important.

I didn't know if it had to be some kind of marine grade stuff of if any regular Automotive antifreeze will do?

Cheers

 

[jhr]

I suspect there is probably a special "marine" coolant, with a price tag three times that of Halfords Ordinaire /forums/images/graemlins/smile.gif. However, I can't see that you could go far wrong using an ordinary coolant, though you might want to choose one that is as environmentally friendly as possible, since your engine(s) will chuck it into the briny when you go back in the water.

 

[Rob H 37]

Yep, exactly

I understand which are better for the environment content wise, but as its that time of year when we all start to haemorrhage (How the hell do you spell that?) cash, I'm taking any opportunity to save a couple of quid!

Any non chandler types on the forum or engineers who can put us straight on whats needed?

 

[jhr]

It's always that time of year for me.

You're not going to believe this, but I've just looked on the Halfords website, and their bog standard anti freeze is £12.99 for 5 litres. Then I looked at the winter service invoice from the yard (Bucklers Hard Boatbuilders) and they have charged me £1.99 per litre plus VAT for antifreeze, therefore £11.69 for 5 litres. This leads me to the following scientific conclusions:

<ul type="square">
[*]It's probaby not essential to use la-di-da antifreeze on your boat (though mine is petrol engined), and
[*]Boatyards are cheaper than Halfords
[/list]

Further research indicates that Pigs may be capable of winged flight and the moon is almost certainly made of green cheese.

 

[TrueBlue]

Ethylene Glycol is said to be Not Very Nice and therefore not PC, however I have some eye drops which contain glycol, and I believe it has been used to tartup some grotty wine awhile ago - but nobody wasitt or died, so I have my doubts about its toxicity, especially as it would get diluted very quickly.

The newer more friendly stuff now available for motor vehicles is supposed to be nontoxic.

The raw water is limited to the pipes, heat exchanger and waterblock sao I would have thought 5l of mix would do the job (rather than 10l as implied above).

 

[spannerman]

The raw water system for KAD 44 and all other 6cyl turbo Volvos consists of pipes from drive to raw waterpump,pipes to oil cooler, then heat exchanger and then charge air cooler, after filling all the above parts of the raw water system you will not see any antifreeze issuing from the exhaust which is your sign that you have filled the system on only 5 litres. It doesn't go into the 'water block' as this is already filled with antifreeze as a part of the fresh water system, and why worry about the cost of the extra antifreeze in relation to the price of a cracked heat exchanger or oil cooler. Personally I call it cheap insurance.
The latest trend in 'Marine' coolant now is 'silicate free', as Yanmar found they had corrosion problems so now specify it as mandatory and all recent Yanmars were recalled to be flushed out and the new type coolant installed.

 

[TrueBlue]

Spannerman,

'Twern't the cost of antifreeze, more the thought of putting more chemicals into the ocean than absolutely necessary.

Shows my ignorance of these engine. Thanks for the feedback / correction.

 

[spannerman]

You are welcome, its a pity more people like yourself don't think about the environment, we use a big trough when flushing engines so we reuse the coolant mix that comes out of the exhaust. Steve

 

[msimms]

I assume this would be the same procedure for an AD31? Thanks.

 

[neale]

Monopropylene glycol is the more environmetally friendly antifreeze, as opposed to Monoethylene glycol, which you will get from Halfords and which is highly toxic.

Neale