Whistling noise

After adjusting belt tension I notice a whistling noise when applying accelerator ,mostly noticeable when stationary . Not sure if it was there before but know noticeable , wondering if its a bearing on the tensioner/idler or alternator any tips to locate actual source of noise would be helpful thank you.

if you have a long screwdriver, you can put the driver end against a non-moving part near the pulley - and listen at the handle end. Or get a similarly long bar and stick a plastic funnel over it to use as an earpiece. This should amplify and isolate noises. This may be quite difficult for some of the pulleys on a hiace though - with the tight engine space. Obviously, be careful of the moving parts, you don't want to catch a belt or a pulley with the end.

Good morning JT69

Pour water on a pulley while it’s running. If it immediately quiets down you’ve found something to investigate.

You can also get a long screwdriver and use it to listen. Put the pointy end on the part and listen to the other end. Bad pulleys make a terrible grinding and weird chirping sound when you do that.

Good Luck and God a less
-JT69

Seam to have resolved my whistling noise , removed driver seat and engine cover checked all bearings connected to belts all ok . The camshaft cover breather pipe was off this seams to have allowed turbo whine to become louder , although whine is still audible it is very quiet and more apparent in the air intake. Fingers crossed all is good.