Seat Inca engine noise and belt handover issue

I have a Seat Cordoba, and your situation sounds remarkably similar to an issue I encountered previously. The engine noise you described, coupled with the serpentine belt malfunction, points towards a potential problem with the idler pulley. Have you inspected the pulley for any visible signs of wear or damage? What is the condition of the serpentine belt itself?

Thank you for your response. Regarding the idler pulley, I have visually inspected it, but I am unsure of what constitutes significant wear or damage. Could you elaborate on specific indicators I should be looking for? Also, the serpentine belt appears to be in reasonably good condition, with no visible cracks or fraying.

Given your description, it certainly appears the belt tensioner is the source of the problem. The lack of visible damage to the belt itself does not rule out tensioner failure. If the tensioner is not maintaining proper tension on the serpentine belt, it can lead to slippage and the issues you're experiencing. It would be beneficial to seek consultation with a qualified mechanic to conduct a thorough assessment. Continuing to operate the vehicle in this condition may exacerbate the problem and potentially cause further damage.

Thank you for your input. I took your advice and consulted a professional. The diagnosis aligns with our discussion: a defective belt tensioner. The estimated repair cost is 455€. While higher than anticipated, addressing it promptly seems prudent to avoid further complications. I appreciate your assistance in this matter.