working out what a noise is before going to the garage

[jshire]

Hi,

2015 Nissan Note petrol owner. I've noticed a screeching sound when driving, that comes & goes but sometimes, especially on longer drives, can be either constant (at low volume) or last more than a few seconds. I expect this might be the drive belt but I know there are other possibilities & also a range of reasons why the belt might be producing that sound. Does anyone know how to work out what it is before going to the garage? It seems sensible to do that if possible. With technology as it is you'd think by now there would be an online library of sounds to check. 
thanks, 

[Trevor]

You could try pouring some water over the belt (not a lot but a dribble) as the engine is running on tickover
If the noise disappears then the belt is 'dry' or loose and would need replacing or tightening
If the noise doesn't go then try the same process on the belt tensioner (dry bearing) and same rules apply

[jshire]

thanks - will try that

 

[jshire]

Hi again,

any rough ideas on how much changing the belt or indeed the bearings should cost from a independent garage? 

thanks.

[jshire]

so, the garage changed the belt, but the noise is still there sometimes. So, i'm back to trying to work out what it might be so I can avoid having something else done that might not need doing. from what I can find online it could either be the suspension or the brake pads. If anyone knows enough about those to suggest ways to tell the difference I'd appreciate it.