engine coolant

[Dragonlady]

Has anybody had any experience or heard anything about Unipart Super Oat?

Thanks Ian

[Silver Surfer]

Does it give the car a red glow? ;)

(Answer to your question...nope..sorry)

SS

[forumadmin]

You mean you buy an NSX and then ask about using non Honda parts or fluids? Be off with you. :)

That's done it for your resale value already. There's no getting back from this now.:)

[Dragonlady]

It was Kaz who picked up on this when we had our health check done.
We have just had a 72k service done on the car after we picked her up and Kaz noticed that the coolant was a dirty yellow colour.
When we enquired with the dealer they replied that they no longer use the Honda fluid, but use super oat as it lasts for five years and is very good for alloy engines.

So hence the original question. Do I flush it all out and replace with Honda, or leave it in?

Thanks Ian

[goldnsx]

Yellow? Do you mean green?

[PeteM]

Personally if you don't know how long that fluid has been in the car then replace it with OEM Honda green antifreeze. I would rather change the coolant every 2 years with OEM Fluid than leave it for 5 years especially as most Nsx'x don't tend to do a lot of annual mileage.

Pete.

[Dragonlady]

Yellow? Do you mean green?

No the stuff that the dealer put in just over a month ago is mucky yellow, and they have advised that it is Super Oat.

[Kaz-kzukNA1]

Hi, Ian. Thank you for visiting my place the other day.

Ah…. Now I understand why it looked so awful. It was more like gray than dirty yellow.

Originally, I thought your dealer mixed Honda Green and Blue coolant but now it is more likely that they didn’t flush the system thoroughly and unfortunately, they mixed OAT and non-OAT one…

Also, they seem to be not aware of the latest Honda Genuine Coolant Type 2.

Each country has different service interval and as I have never used Honda UK service, I don’t know the latest UK information but in Japan, if it was factory filled with this Type 2 coolant, the service interval is 11years or 200,000km (about 125,000miles) for the first time and then 6 years or 120,000km (about 75,000miles) thereafter.
I’m quite sure the latest UK service interval for Type 2 coolant would be similar figure such as 5 years or so.

[Edit] Honda Type 2 Coolant is Blue and not Green.

The gray colour of your coolant looked to be the result of debris created when OAT and non-OAT coolant were mixed. I could be wrong as I have never used Unipart but to be on the safe side, if I were you, I’ll ask your mechanic to flush the system thoroughly and replace it with Honda Type 2 coolant.

For your reference, even when I replace all of the coolant hoses, I have to flush the entire system at least 4 times. If you are not replacing the hoses and just replacing the coolant with different type, then you’ll probably need to flush the system 5 times or more.

Hope this will help.


Regards,
Kaz

[goldnsx]

Continental Europe service books state every 4 years but I regard this as a very good selling tactic and nothing else. ;) On things you touch every 6-10 years I'd go with Honda OEM. :)

[Dragonlady]

Thanks for that.
How much water does it hold? and would you use tap water for flushing through as I know it is distilled water when finally filling the system, or filtered rain water.

Thanks Ian

[amo]

iv just used normal tap water to top up mine
welsh water is good for everything lol

thx amo

[Kaz-kzukNA1]

Thanks for that.
How much water does it hold? and would you use tap water for flushing through as I know it is distilled water when finally filling the system, or filtered rain water.

Thanks Ian
Hi, Ian.

If you are going to use Honda Type 2 coolant, then it is already pre-mixed (50/50) so you don’t want to add any water.

As I live in hard water area, I use filtered rain water to flush the system at least 4 times even when replacing all of the collant hoses (more than 20 of them...).

Having said this, unless you are replacing the coolant hoses, you won’t be able to drain the system completely empty. You’ll end up with about 20-25% of the fluid left in the system even after following the drain procedure on the manual. Because of the shape of the hoses as well as the pipes, you won’t be able to drain the fluid in the long pipe for the Eng Oil Cooler, the pipes/hoses at the centre bottom floor, inside the heater core and the pipes/hoses at the radiator.

The coolant system will hold about 16.0L to 16.5L including the amount inside the header tank depending on your model. If you don’t replace the hoses, you’ll need about 12.0L.

Honda Type 2 coolant, 5L container: 08CLA-G01-8L0
GBP14.61+VAT

Although it says 5L, it actually contains about 5.4L.

Regards,
Kaz

[Dragonlady]

Thanks for that Kaz, last question (maybe), is there a drain tap or do you just disconnect to bottom hose of the radiator?

Would having the car on an angle help drain some of the remaining coolant?

Thanks Ian

[goldnsx]

Let me answer you. There are two white plastic screws on the radiator, one upper, one lower. They look like a small butterfly. Replace the o-rings BTW. The upper one drains the air while refilling. Don't close it before coolant is coming out while refilling.
Do not touch the hoses unless you replace them.
Angle: It's normally good to have the nose of the car a little bit down but not by much.

Looks as if you do it yourself for the first time. Check the manual for the procedure. You don't want air pockets within. To get a guess I'd measure the amount of coolant you've put in.

[Kaz-kzukNA1]

Thanks for that Kaz, last question (maybe), is there a drain tap or do you just disconnect to bottom hose of the radiator?

Would having the car on an angle help drain some of the remaining coolant?

Thanks Ian
Hi, Ian.
As goldnsx pointed out, looks like you or your mechanic never carried out the procedure on NSX.

First, please read the manual for the coolant service. You can check it through NSXPrime Wiki or Dali website.
Then, you will understand the position of drain tap/bolt as well as the air bleeding procedure.

Please remember to set the A/C CCU target temperature to be at 32degC throughout the whole process.

For your reference, there are 2 drain bolts on at the engine block (Front & Rear) but you will get just a small drip from the Front block after draining the coolant from other places so just open the Rear one. Use some sort of hose to drain the coolant from here as you don't want your coolant to touch the header. It smells bad if you don't rinse it well afterwards.

There are another 2 drain bolts located at the centre floor pipes hidden by the long plastic cover running at the middle of the chassis. Be prepared to get wet when you open these 2 bolts.... 2 washers to be replaced.

And there is another one at the bottom left side of the radiator. It is red or white drain tap. O-ring to be replaced.

Addition to these drain points, you have 4 bleeding points. These are located at the thermo cover, engine bay coolant pipe through firewall, heater core pipe under the bonnet and at the top of the radiator.

It is best for you or your mechanic to follow the sequence described in the manual for air bleeding.

I never used the method to drain/fill the coolant by tilting the car. As I always replace the hoses and use vacuum fill method for coolant service, I can't provide you with my experience on this.
Considering the up/down/left/right shape of the coolant hoses and pipes, it may help for some parts but then could trap more water/air for other areas.

I can't stress enough the importance of bleeding the air from the coolant system so please read the manual several times and follow the procedure.

Regards,
Kaz