I heard that air bubble results when you change coolant the wrong way. How can I avoid it? What is the proper way of changing coolant? When I search the forum, no one talked about air bubbles. How big of a problem is it?

 

Typically there are air relief valves on the radiator and engine body to allow the air to escape.

 

so there isn't anything that I need to open or close on my 2k? Please clarify.

 

You would need to open the valves while filling and then close them when you are done (fluid starts coming out). I believe the one on the radiator uses a hex bit. I don't know about the engine body ones.

 

I just flushed and refilled 2 Maxima's w/o any problems. All you have to do is slooowly refill the radiator and no air gets trapped.

 

I just checked my 02 ESM and karguy is correct. No relief valves on the 02 Maxima. My wife's Quest needed the relief valves opened and I assumed the Max would be the same. The ESM says fill the radiator and reservoir tank. Run the motor and then check (and refill) radiator and reservoir.