Good evening Scotty / Moderators!

My stepdad has a 2007 Toyota Tacoma TRD that's been making a loud whining noise while idle and getting louder and changing pitch while driving. The truck has been an absolute tank with 450,000 Km on it so far! At first I thought it was the transmission, being that it hasn't had its fluid changed since it rolled off the lot (its a closed system) but after watching a few of Scotty's videos I believe that its one of the modules ran by the timing belt having a worn out bearing. My reasoning for this is because the sound still occurs during idle, and when I put my head under the front wheel well to listen, it becomes very loud and pronounced. What are your guys thoughts? any ideas on what it could be?