Coolant change really necessary?

Momac

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In all the years I have owned cars I have only once been advised to change the antifreeze and that had disastrous consequences.
My boat engines have green antifreeze and it is certainly more than 3 years old.
I have seen advice suggesting coolant change every two years.
Is coolant change essential in the UK climate?
Will my three year old (or older) coolant now not offer protection against frost? Or perhaps it is just the level of protection is reduced?
 
If you don't change it on the KAD series engines, the coolant gradually loses it's corrosion resistance, and goes brown from rust as your engine slowly dissolves from the inside outwards.
You can spot engines where the coolant has not recently been changed, as the expansion tank is also brown, which isn't a good look.
 
In all the years I have owned cars I have only once been advised to change the antifreeze and that had disastrous consequences.
My boat engines have green antifreeze and it is certainly more than 3 years old.
I have seen advice suggesting coolant change every two years.
Is coolant change essential in the UK climate?
Will my three year old (or older) coolant now not offer protection against frost? Or perhaps it is just the level of protection is reduced?

It is the corrosion inhibitor additives that deteriorate.

Www.solocoastalsailing.co.uk
 
In all the years I have owned cars I have only once been advised to change the antifreeze and that had disastrous consequences.
My boat engines have green antifreeze and it is certainly more than 3 years old.
I have seen advice suggesting coolant change every two years.
Is coolant change essential in the UK climate?
Will my three year old (or older) coolant now not offer protection against frost? Or perhaps it is just the level of protection is reduced?

The coolant should still offer the same degree of frost protection if it has not been diluted by topping up with water however the corrosion inhibitors in a conventional, low silicate, type of antifreeze may, as already suggested, have deteriorated and no longer be offering an adequate degree of corrosion protection.

A two year change interval is normally recommended for the conventional ( eg Volvo green) antifreeze.

More modern engines use the long life. "organic acid technology" (OAT) type of antifreeze which has a longer service life but you should use the type specified in your engine manual ( conventional unless OAT is specified) and change at the recommended service intervals Take care not to mix conventional and OAT types!

You should also ensure that the coolant in your car is changed at the recommended intervals although any car less than 20 years old will almost certainly be using the long life, OAT type
 
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I have seen others that have become brown but my coolant has remained green.
However I am thinking a coolant change should be added to the engine service routine this winter.
 
I have seen others that have become brown but my coolant has remained green.
However I am thinking a coolant change should be added to the engine service routine this winter.

Its a simple enough and cheap enough job. Not sure why you wouldn't change it!
 
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