Hyundai i40 - 1.7 crdi - Coolant replace

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Mon 28 Nov 2016 14:06
Hyundai i40 - 1.7 crdi - Coolant replace - TopScot

I'm wanting to replace the coolant for the winter. Does anyone know if the Hyundai diesel's have a sump at the bottom or if I need to disconnect the hoses to drain? Thanks in advance

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Mon 28 Nov 2016 15:51
Hyundai i40 - 1.7 crdi - Coolant replace - John F

I'm wanting to replace the coolant for the winter.

Why? Is the antifreeze component of the coolant an optional extra on this model?

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Tue 29 Nov 2016 08:27
Hyundai i40 - 1.7 crdi - Coolant replace - skidpan

I'm wanting to replace the coolant for the winter.

What is Hyundai's recomendation. If they use the same stuff as Kia (very likely) ours was 5 years.

If you are still within the life of the antifreeze and concerned about its efectiveness simply get the freeze point checked at a local garage, if its OK leave well alone.

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Wed 30 Nov 2016 12:42
Hyundai i40 - 1.7 crdi - Coolant replace - RichardW

It's not the freezing point that goes off - this pretty well stays constant as long as it is not watered down - it's the corrosion inhibitors that give problems. Modern OAT coolants good for at least 5 years and probably 10.

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Wed 30 Nov 2016 15:11
Hyundai i40 - 1.7 crdi - Coolant replace - John F

it's the corrosion inhibitors that give problems. Modern OAT coolants good for at least 5 years and probably 10.

Probably the life of the car. The inhibitor doesn't 'go off' and only 'gives problems' if it is neutralised by oxygen in the coolant. Modern cooling systems are sealed so that once the oxygen molecules suspended by the coolant water have been used up, no more can get in. I have no intention of replacing the oxygen-free 16yr old pink coolant in our Focus. The inhibitor has only ever been additionally taxed by a mere 200mls of rainwater added in the 13yrs of our ownership. Corrosion cannot occur without oxygen.

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Wed 30 Nov 2016 16:59
Hyundai i40 - 1.7 crdi - Coolant replace - RT

it's the corrosion inhibitors that give problems. Modern OAT coolants good for at least 5 years and probably 10.

Probably the life of the car. The inhibitor doesn't 'go off' and only 'gives problems' if it is neutralised by oxygen in the coolant. Modern cooling systems are sealed so that once the oxygen molecules suspended by the coolant water have been used up, no more can get in. I have no intention of replacing the oxygen-free 16yr old pink coolant in our Focus. The inhibitor has only ever been additionally taxed by a mere 200mls of rainwater added in the 13yrs of our ownership. Corrosion cannot occur without oxygen.

Rust needs oxygen - but other forms of corrsion don't, particularly engines with iron blocks and alloy heads.

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Wed 30 Nov 2016 17:58
Hyundai i40 - 1.7 crdi - Coolant replace - gordonbennet

Original red Toyota coolant change due, would it last another 5 or more years i don't know possibly, but £25 just bought me 5 litres of genuine Toyota concentrated coolant delivered, i know for sure that any single item the inhibitors in that coolant save will be in multiples of, or tens of multiples of, that £25, so changed it will be on Sunday.

There are some things that are simply not worth skimping on, lubricants filters etc are ridiculously cheap compared to the things they protect.

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Wed 30 Nov 2016 21:31
Hyundai i40 - 1.7 crdi - Coolant replace - RichardW

Nothing to do with oxygen - the glycol breaks down with heat and forms acid species which attack various components. The corrosion inhibitors buffer the coolant to stop the attack. If it's still clear then no reason to change it.

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