15-12-2016, 11:05 PM
Welcome! Have a watch of the aux belt with the engine running, if you can see the belt bouncing anywhere it'll be the next item in the direction of belt rotation, if that makes sense. Hopefully just a tired aux belt, certainly sounds like it. Take it off and check all your pulleys and tensioners for any play to be sure - you'll need a 15mm spanner and strong hands or a bar/another spanner linked into the first to release the tensioner. Be aware it'll spring further round when released fully than it will with the belt on (apologies if i'm teaching you to suck eggs here), can be a pain to get the right angle to lever it back enough to refit the belt, some people find it easier from underneath with the arch liner out.