coolant color, blue or green ?

[hangout]

I have the 1994 twin turbo. everything stock with 86k miles and the the previous owner was a car guy, he told me he changed timing belt, water pump, flush the coolant, but not the thermostat..

last week it was so hot in NYC, while I drove it almost an hour to work in the nice and cool morning, everything is fine and the temperature gauge was level.
afternoon, it's around 90 degrees strong sun outside, I drove it home, I found the temperature on the Z was strange.

the temperature goes up and down. it's not by the speed I was driving, in the traffic or hiway maybe the same.
it feels like the coolant become hot,the the car fan cool it down. I checked the coolant level, it's normal, and it's green color. My friend told me, the nissan OEM coolant might be blue color? is it right?

I'm thinking to change the coolant sensor and flush it to the OEM coolant. will it help? (most simple way)
which type of coolant I should get?
blue or green? any other suggestion ?

Thank you

[BlackWidowZ]

You have to drain all of the coolant out of the radiator and engine to change the waterpump. Unless he put the old coolant that he drained out back into the car than it should have new coolant.

Just you the normal antifreeze its green.

[NolimitZ32]

^ this, and I've always used yellow to add, the mix with any type any color stuff. Most important thing with your cooling system is to use distilled water.

[hangout]

yes, I'm sure it's the new coolant in the Z now.
I was just wondering if the guy use the common type on the market will cause this issue.
does the Z turbo require special coolant for it ?

[NolimitZ32]

No special coolant, from all my research it seems that the Honda Blue and BMW Blue are actually the best coolant to use in any car due to chemical properties and purity. However they do not mix with any other coolant and therefore require a complete flush before installing and since you have green in there now I would just stick with it and use the yellow "Any Year/Any Model" to top off.