I have a 2005 Dodge Ram Hemi. I recently had an egr valve changed because it lit up my check engine light, I thought maybe it also had something to do with the whining noise I'd been hearing. The mechanic said that it was one of the belt pulleys. Is it really that difficult to figure out which pulley bearings are going out? I've had someone listen with a stethescope and decide that it was the alternator, so I got a new alternator, still whining. Next I changed the belt tensioner assembly, still whining. I'm getting sick of buying new parts and the noise is getting really bad. Anyone have any ideas on how to figure out what's going on without using trial and error?

 

Another question...how long does it take for the computer to reset? When I replaced the alternator I unhooked the battery and now my truck isn't passing emissions because the computer hasn't reset yet.