First, you have a known issue with fan/shroud, so take care of that and see what you get.
You can also use a hose as stethoscope and listen yourself. I use a 5' section of 1" d flexible electrical conduit from HD and it works great...just be careful around moving things.
Also, check your belt from the side to see that it's square across all the pulleys.
If the wp is wobbling, it could be internal to the wp, or it could be motor mounts.
If you do replace wp, I'd suggest you consider doing more with your cooling system if you haven't done anything else on it...therm, hoses, ET... I like low-hanging fruit...which is why I'll leave it to Mango's sticky thread to 'pitch' cooling system work to you! LOL
I'm so depressed. No one wants to come see me. :(
Mangofy your E46!