I have noticed mine blowing hot air on the passenger side more than the drivers too. I remember it happening on New Years Eve last when we went to watch fireworks... than when we went to my Mother-in-laws around X-mas. And again when I took my wife to the mall so she could return some things I got her for X-mas that "didn't fit" (not sure how a blender and new pots and pans "don't fit" but that's a story for my therapist).

Anyway, I'll ask my wife to check that hot air issue, it seems to happen... oh. I see what happened now.

Nevermind.

 

It's the heater core, I've done a few of them. All were '08 models and they all had been partially plugged up on the one end. Unless you have lots of patience, lots of time, access to an a/c machine and are very mechanically inclined I'd let someone else to it.

 

When you say it is the heater core and you have done a few of them, do you mean they needed replaced or flushed? The dealer has flushed mine twice within a month and still have no heat.