2019 Tahoe, 5.3L with over 130k. A couple days ago the wife told me she heard a noise from the engine, I listened to it quickly as she was about to leave for work and it sounded like the serpentine belt, told her I would look at it later. Today I hear its slightly louder, open the hood and there's oil all over the belt and on the front of the engine. Leak has to be coming from the front of the engine in order to get on the belt. Oil pressure is fine when the engine is running and the dipstick still shows the oil level is fine. No white smoke from the tailpipe, so I don't think its the head gasket. There was a small amount of oil residue around the open on the vacuum pipe on the driver's side when I pulled the airbox off the throttle body, but the box is clean inside and so is the throttle body. Its currently sitting at our business, so I plan to go back with some brake cleaner, clean what I can, and test to see if I can find the leak, but I'm looking for places I should pay attention to.