I think there may be air trapped in my cooling system since the heater seems to blow colder air when idling and only gets hot when the engine is revving. I tried searching the forums and apparently there's supposed to be a air relief screw near the rear passenger side of the engine bay, but my 2004 coupe doesn't seem to have the screw that everyone seems to be referring to. Instead it has what looks like an air valve that you see on tires with a green cap on it. Can somebody let me know what exactly I have to do to bleed/burp it?

 

thats green valve is for evap, dont use that one. i look today and see if i see one. also did you do some kind of coolant service to it or something?

 

Bleeder valve is on coolant line at rear of engine bay on passenger's side. Below main engine harness.

 

For those that have changed their coolant, what's the brand/spec you used?

For the OP, you might try putting the front of the car on a set of ramps and open the radiator cap. Air should slowly work it's way out. Not sure if have to have the car idling or not. You might blow water out that way

 

Our cooling systems are notorious for being difficult to bleed. I recently used a funnel that I borrowed from rookie and it worked great.

http://www.autobodytoolmart.com/p-15...nel-24610.aspx

 

I actually just found it, I guess I wasn't looking hard enough! I'm not really sure exactly how to go about doing it, but if I just start the car and loosen the screw will the air work its way out of the system? Or do I have to do anything else more specific?

 

once you loosen it up it should start bubbling out coolant if theres air in your system. if not it'll be a solid drip. you could also try doing what jeff92se did. seems more for old school 3rd gen maximas though =X

 

All the cars I had I used 50/50 Prestone coolant and I flushed the system once or twice with distilled water first. Comes in a yellow bottle. It's even at most grocery stores.
I'm getting ready to change my coolant before the climate gets any hotter here.

 

DIY Video: Coolant Service

 

Great video.

 

Dude - why does the video stop right as you are starting to pour the coolant in!! I need to see how this ends...so suspenseful. Gotta get my popcorn and a coke.

 

Try refreshing the page and wait for the video to load completely before playing it.

 

Dude...you are awesome...why did you replace the Rad cap? Was yours busted?

 

it actually was fine I think.. but I figured it would be nice to have a new one anyways. Of course, it's always best to inspect the old one for wear, etc, and replace accordingly.

 

You can squeeze the top or bottom radiator hose as you pour coolant in the radiator neck to get the air out. It's how I always did it on all the cars I owned including 2 4th gen Maximas.

You can also remove the lower radiator hose to drain the coolant out.