Seat Leon Belt Handover Issue

I also own a Seat Leon, and your described symptoms bear a striking resemblance to an issue I encountered previously. The belt squeal, coupled with the cessation of the belt-handover function, strongly suggests a malfunctioning tensioner pulley. Before proceeding, could you elaborate on the specific engine noise you are experiencing? Furthermore, has the idler pulley been inspected for any signs of wear or damage? In my case, the defective tensioner pulley caused premature wear on the belt, necessitating its replacement as well.

Engine noise is kinda like a whirring sound, gets louder when I accelerate. As for the idler pulley, I haven't checked it myself, to be honest. Is that something I can easily inspect, or is it more of a mechanic kinda job?

The whirring sound you describe further reinforces the likelihood of a faulty tensioner pulley. While a visual inspection of the idler pulley is feasible, assessing its internal bearing condition often requires specialized tools and expertise. Given the potential for consequential damage to the engine if the belt fails completely, I would strongly advise against attempting a self-repair without adequate mechanical proficiency. I recommend consulting a qualified automobile maintenance technician for a comprehensive diagnosis and subsequent repair. They should be able to accurately assess the condition of both the tensioner and idler pulleys, and provide a reliable solution.

Thanks a million for the heads-up! Took my Leon to the shop and, yep, belt tensioner was toast. They quoted me 455€ for the whole thing. Ouch. But at least the belt squeal is gone and the engine doesn't sound like a bag of nails anymore!