Toyota Repair: 2000 Corolla Serpentine belt, serpentine belt, nut bolt

Question
I want to remove the belt and check to hear if the noise at cold start is due to the belt tensionser. My problem, I can't get a wrench or socket on the nut/bolt for the idler pulley (tensioner). I tried 12-pt. 13 mm and 14 mm socket and combination wrench. I also tried 6-pt. 13 and 14 mm socket and none seem to fit properly. Does this require a special tool? If so, what and where can I get one. Do you have any advice on cold start noise that goes away after engine is hot? I have been advised by a Toyota mechanic to check the belt tensioner and the timing change tensionser that I believe is driven by oil pressure.  Thank YOu.

Answer
Tom,

There is a special tool for removing your serpentine belt. It is a long thin bar designed to get in those tight spots. It is available at most auto parts stores. As for your Corolla I am not sure what type tensioner that car uses. I have not had the opportunity to work on one yet.