[Krisp97]

Originally Posted by SwankPeRFection

Lol, having the king of idler and tensioner pulleys engine (ie Audi’s supercharged 3.0) in my S4, I can tell you I’ve spent some quality time with my front end in service mode fixing this same type of issue in the past. Let’s just say that when you go with higher crank pulley sizes to make more power, changing the accessory belt becomes a dance of loosing tensioners enough to swing completely out the way so you can remove or partially remove an idler behind them to be able to slip that belt off. Yeah, fun. It’s been my findings that steady squealing that doesn’t change intonation much is usually a static mounted idler and if there any kind of wha wha intonation affect to the sound it’ll usually be the tensioner, which depending on spring tension health can deflect quite a bit as you rev the engine either a little or a lot. Either way, the issue is the bearing in them and nothing more. On the S58, since it’s just one small belt and package, loosen the tensioner, take the belt off to reduce drag and spin either pulley by hand. The problem one will usually make a small mouse sound as you spin it back and forth or it’ll feel a tiny bit gritty on the spin.

Now imagine having this sound constantly and be RPM based… had that happen in a WRX years ago and it was one of the guide/idler pulleys for the timing belt. That was fun getting the dealership to trust what I was saying and to just dig in there and find the goofy one. First time they’d seen that. Lol

I wouldve imagined diagnosing it wouldve been that easy but it wasnt as mine was temperature based and also something to do with relative humidity. Glad this is over.