Confused over antifreeze.

[colin_dev]

Hello,

I would like advice please. What I thought would be an easy job is giving me stress. Perhaps I worry too much.

The story so far:-
My Jeanneau SO389 was built in 2015.
I purchased it new in late 2016.
It was commissioned in early 2017.
The engine is a Yanmar 3ym30.
The engine was professionally serviced in autumn 2017 and 2018.

I want to change the antifreeze/coolant but have no idea what type it is, the only thing I know is that it is a greeny blue colour, this I have drained out. I do not know if this was put in in the factory in France, during commissioning or during the servicing.

The Yanmar manual states that either a specific Havoline or Texaco antifreeze should be used, but these do not seem to be available in the UK.

I have read on this forum that different types of antifreeze cannot be mixed. The OAT, IAT, silicate comments baffles and confuses me. So I thought the best thing to do would be to use the Yanmar branded antifreeze, that way I know I am using the correct stuff.

I purchased the antifreeze from the local Yanmar agent and found it to be orange in colour.

So knowing that different types cannot be mixed I am currently in the process of flushing the engine with deionised water. However on another YBW thread I have been told that water alone is not sufficient and that oxalic acid solution should be used.

I am now thinking that I should simply revert to an antifreeze of the same colour as I took out, despite it not necessarily being the correct type for the engine.

I feel as though the hole I am in is getting deeper! Wish I had never started this job.

Some simple advice would be much appreciated.

 

[Fr J Hackett]

The problem with antifreeze is related to corrosion of heat exchangers and primarily relates to old types, as you have an approved type for your engine just go ahead and use it there will be no problem of mixing with any minor residue of the old and flushing with deionised water is a little OTT but won't harm.

 

[Refueler]

As post #2 .............. bung in the Yanmar anti-freeze you bought and feel good ....

 

[RJJ]

I am working on the following advice from Volvo

If your engine needed a flush, it should be oxalic acid followed by bicarb of soda followed by fresh water. And finally refill with whatever antifreeze you like.

Without knowing your specifics re colour schemes, I can't give you a view on whether flushing out was necessary in the first place.

 

[RichardS]

As I stated in the other thread, 3YM30s were supplied new with OAT antifreeze. It's called Longlife antifreeze in the Yanmar manual but that's just the generic name for OAT or organic acid technology.

The older style antifreeze is called silicate or IAT, inorganic acid technology.

As I explained in the other thread, flushing is not a requirement other than to remove crud or to remove an older version of OAT because it was a different colour and you want to keep the colour "pure". As you already have OAT/Longlife in your engine, flushing is not a pre-requisite for any technical reason.

The original OAT coolant in my 2008 3YM30s was blue but I've now replaced that with pink/orange Halfords OAT. Pink/orange seems to be the default colour for OAT these days and the Yanmar stuff is probably made by the same people who make the Halfords stuff. However, just to prove the rule, the OAT used in my Son's new Honda motorbike and my wife's new Mazda is blue.

VicS brought up the issue of chemical flushing relating to a change of antifreeze type in your other thread so I don't really understand why you have started a new thread if that's what you would like to discuss.

Richard