When I floor it and the car is accelerating, I've noticed that the car has a mechanical whining noise to it. Don't have a turbo or anything either. Also when the car hits about 4-5k RPM I notice a little hesitation as if its catching up or something; It accelerates smooth until 5k and then it stays at that level for a moment and keeps going after. This has been happening since I got the car. Its a 2016 Corolla le. Not much has been done to it besides rotors and brake pads that have been changed
if you are a 1st time Corolla owner... what u describe is "Corolla normal"