Squeaky drive belt

The belt is on the right side of the engine bay. Just like the port and starboard sides of a ship do not change when you are at the front looking backward or at the back looking forwards, so it is with cars. Left and right of cars is as it is sitting in the driver's seat looking forward.

I'm not sure what they mean by automatic but, yes, there is no spring tensioner. The tension on the belt is manually set by tightening or loosening the adjustment bolt which acts on the idler pully.

The belt, for sure should be changed if it is damaged/cracked (on the inside). If the belt is in good condition, all that might be required is tensioning the belt to the correct deflection.

The only other item that might need to be replaced is the idler pully if for some reason the bearing is damaged and sloppy.

 

Undo the tensioner take off the belt then spin the little wheel the idler right there at it If it sounds like crap just replace it it's like $9. If you're in a foreign country where that's not the case other idler pulleys may fit The center hole in the OD is what's important you'll be reusing your bolt. Now you can really see the belt well and since it's off just replace it many of them go hundreds of thousands of miles and never get replaced seriously and when they come off they're lightly cracked nothing really serious but they're dry and dry equals noisy.

 

Is it safe to assume "mileage" means 341k miles on this car or can "mileage" also mean km?

 

A multi-rib belt "squeaks" when the pulleys are out of alignment, or if the belt is slipping (due to being loose or contaminated with some type of fluid).

The Gen2 Prius design is pretty simple - crankshaft pulley, water pump, and a manually adjusted tensioner pulley. You would need to have the belt removed to inspect everything.