I have just purchased this used civic 2000 with 40k miles and it has green coolant and i dont know if it is old honda when it used to be green coolant or prestone or some other green stuff. so i dont know if i can mix the two so i dont know if i should

1. just drain the radiator and refill with new honda blue coolant

2. drain the radiator and fill with water and the run the car for 10 min with the heater on and drain and repeat until only water comes out. then repeat and fill with hondo blue coolant until it is pure blue which would probably take about 5 gallons of the coolant to refil. i was told not to put water in the system because it rusts it. not even for flushing. so that was put a stop to this method if true.

3. do same as above #2 but instead just fill each time with blue coolant until it is all blue. but i risk the mixing of the coolants and i have been told the mixing stops the long life protection effect ie 100,ooo miles and turns it into 2 years protection. and worse yet i have been told when mixed could turn to slugey mixture or something worse.

4. drain the radiatior and drain the engine coolant block by taking out some bolt on the engine. but i cant figure out where it is. i looked and cant find it. someone said that you also have to bleed it from somewhere to get some air buble out or something. if you know how to do this method please let me know because it seems to be the safest way ie no mixing of fluid and no adding water in the system. on the other hand someone said the thermistat has to be removed to do this method and i am scared of doing some major things on this 40k mile car. if i can get away with something as simple as drain and file.

 

anyone?

 

Are you serious? The search button is your best friend. It's magical, you type your question in the search box and it gives you the answer.


https://honda-tech.com/zerothread?id=1424191

 

thanks man!!

so can blue honda mix with green of unknown brand?