Originally Posted by ShawnOk

So I've attached a photo and after a visit to the dealership they said that it could be a serpentine belt problem, a pulley problem, or a tensioner problem. They said since they were going to take apart most of the relevant items, I should replace the timing belt, water pump, gaskets, etc at the same time to avoid future problems. They quoted the entire job at $1135 including parts and labor. The photo with the red arrow is the culprit where the squeal occurs. I was informed that the water pump is actually interior to this area and basically "inside" the engine. After consulting a tech who exclusively works on Toyota and Lexus, the consensus was that it's only the serpentine belt that is giving me the squeal and thus will start with the small problem first and replace only the serpentine belt for $140. I will keep this thread posted with the results. Thanks for all the advice everyone!