Hello , I'm new to the forum but I've always owned toyotas. Actually I rebuild engines on my spare time(mostlly 2ZZ-GE engines for the celica and Lotus)
I own a 2007 sienna LE.
I wanted to give you a heads up on the water pump. After having 105 000km on the odometer it let go. Having past the warranty period I was quoted from the dealer a 6 hours job and about $200 for the part alone. The symptoms will start with the air condition system behaving erratic (cold /hot). The system will put itself in a recirculation mod to compensate and it will be physical impossible to get it in fresh mod. I'm guessing it has something to do to with the a lower coolant level. It's not very complicated of a job to do but involves numerous steps to get at it!
The pumps bearings are at fault here. It was confirmed to me from some friends (mechanics) that work at a Toyota dealer....the 3.5 V6's have been having all their pumps changed at about that millage. Look for some slight leaking ( it's quite hard to look at, as it's very tight) and check your coolant level.
I didn't check mine ....as I thought "This is a Toyota not a Volkswagen!.. the pumps are supposed to last a long time!" : But please do it before you reach that 100 000km /60 000 milles mark.