Coolant

[charlie]

I am sure advice to use genuine Honda coolant is sound. The coolant in my NA1 remains original green. Is this still available? If not, is latest Type 2 (Blue) wholly compatible when topping up?

[pralognan]

The corrosion inhibitors in the coolant are gradually depleted over time,hence the recommended replacement of the coolant every four years. I would drain and start afresh with Type 2 if I were you. I spent 30 years making OEM radiators including for Honda.

[charlie]

The corrosion inhibitors in the coolant are gradually depleted over time,hence the recommended replacement of the coolant every four years. I would drain and start afresh with Type 2 if I were you. I spent 30 years making OEM radiators including for Honda.

Many thanks.Willdo.

[goldnsx]

Not sure but I recall a thread of Kaz somewhere here on the forum that mixing blue and green is not the best idea in the longterm. For short usage it's surely better than low on coolant. If you still have the green one in it I guess you can't get anymore I'd do a full flush with Type 2 (blue). If you want to have it completely out you should loose the coolant hoses in the middle under the car as they contain around 2l I guess. But takting them off is like replacing them anyway. Then you're not far away of changing all hoses and so on...
Mileage of your car?

[charlie]

Mileage is 48k

[Kaz-kzukNA1]

Not sure how old your coolant is but some of the Honda garages in UK are using 'Pro Honda' or whatever it's called Type 2 coolant that has green colour.
It has the Honda 'wing' logo mainly used for the motorcycle parts or on very old automotive parts label.
There used to be (and possibly still out there) green Type 2 coolant on the market sold mainly for the motorcycle parts.
As far as I know, it has shorter maintenance cycle (every 2 years??? not sure as it was such long time ago when it was used as the NSX factory filled coolant) than the blue Type 2 one (good for 5 years) but I could be wrong.

Please note that some of the Honda garages are using Castrol green coolant as well.

As long as you are 100% sure that the green one in your cooling system is the old green Type 2 coolant, then it can be mixed with the blue Type 2 one without causing chemical reaction.

However, if your coolant is already old (like more than 1 years old) or if you are adding more than 500cc or so, I don't recommend mixing them because you are better off changing the entire coolant or you have other issues.

If you mix them too much, the colour turns into like black and if the green one is not Type 2, you could cause chemical reaction and it could generate all sorts of flaky debris, etc that could take ages to flush out.


By the way, under normal circumstances, you should not need to top up the coolant until the next cooling system service.
If you have to, you have problem.

Honda blue Type 2 coolant is good for 5 years but I normally recommend replacing it bit earlier like every 4 years as even when you replace all of the coolant hoses and the radiator, fair amount of coolant is left inside the eng block and the surrounding sections.

If you track your NSX, many NSX owners in Japan are diluting the Type 2 blue coolant down to 30% mixture for increased cooling efficiency but replacing it at least every 2 years or earlier.
If street driving in UK, just use the standard 50/50 as the humidity is nothing like the summer in Japan and max air temperature doesn't hit over 40degC.


Kaz