Hi, just bought a 15' i30 34k miles last week. No trouble at all other than battery for the first week (dealership replaced before I even picked it up as it had gone flat through lockdown lol)
Today I put it through its paces on a quick dual carriageway and at one point upon hitting 5th gear it began creating a whining noise from the engine that I could hear faintly over music. I turned music off and opened windows on a slower road, it had gone away but kept coming back when I would release the clutch and accelerate. By the time i'd got back home and was doing around 20mph in 2nd gear around our cul de sac, it was fairly loud and constant.
Any ideas? I've booked in with Hyundai for a 'free health check'