Seat Mii belt handover problem

That sounds eerily familiar! I had a similar issue with my Mii. Was the engine noise particularly noticeable during idle or acceleration? How's your engine performance been lately? Have you checked the idler pulley as well? It could be related to the belt tensioner. Is the timing belt okay?

Yes, the engine noise was terrible when starting up, and my engine performance has been suffering. I haven't checked the idler pulley myself. When you had the issue, was the belt-handover also not working anymore? And how did you end up resolving the issue?

Ah, that's almost certainly the belt tensioner then! It's a common issue. I'd recommend getting it checked by a professional. Replacing the belt tensioner should sort it out, but it's best to have a mechanic confirm and do the work. It could affect your timing belt if left unattended!

Huge thanks for your help! I took it to a mechanic, and you were spot on. It was indeed the belt tensioner. They replaced it, and the total cost came to 455€. Engine performance is back to normal, and that awful engine noise is gone. Really appreciate you sharing your experience!