Name this noise
 

I have a 2005 Silverado 1500 Crew cab and it has been giving me some issues. Everytime something gets fixed under warranty something else seems to happen. This is my most recent noise that I dont know where to start to diag it. This noise is not always there but it is often present when it is damp or cold. It increases speed and pitch when I accelerate and is there during idle. I have replaced the belt a few times and it still persist.

What do you think? The great thing is that when I take it to the dealer it stops and I cannot duplicate it.

Can you name this noise;
http://i299.photobucket.com/albums/m...ethisnoise.jpg

Have you tried seeing if the belt needs changing or taking the belt off and check each pulley. The damp or cold thing make me think its the belt but you can check the pulleys and make sure you dont have a bad one.

I dont think that it is the belt because I have replaced it three times and everytime I replace it the old one looks as good as new. When I do replace it however the noise will go away for a few weeks.

I think it could be one of the pully's but I am not sure how to check them for sure.

Sounds like a bearing getting dry... given the age of the truck I would consider replacing the idler pulley, have you also replaced the AC belt?

Update,

The noise has been present for some time now and increases pace when I accelerate and slows down when I let off the gas. The noise is also constant when at idle.

I replaced the idler pulley with a Gatorback replacement pulley and that did not eliminate the noise.
I then replaced the tensioner pulley because when I took my old one off and shook it, it had a rattle. I picked up a Gates pulley which is made in Canada but noticed the bearing is made in China. This did not eliminate the noise either.

I am not sure what else to replace. It sounds like the noise may be comming from the alternator pulley but not sure. Is this pulley replaceable?

The AC belt and the Serp belt are new and I have replaced my serp belt about 5 times in the past two years. Everytime I do this the noise stops for a week or so.

Sounds like water pump, or at least on the video in that area. If you suspect alternator, yes the pully is removable, however it will be the bearing. My advice, remove the belt, check for radial, and axial play at the pulley, if you have some or is noise, I'd replace the alternator as a unit.

Hmm,

I didnt think about the water pump. Anyway to "confirm" a bad water pump? I believe that my water pump and alternator are still covered under my extended warranty after my $100 deductible. I wonder if I should just take it to the dealer and let them figure it out. It would be worth it if there is a repair that is covered and cost more than $100

buy a mechanics stethoscope for $25. Remove the metal end from where it attaches to the tube of the scope. with the noise active, put the scope tube near each pulley. Check the a/c tensioner also. The bad pulley will be loudest.

obviously, be carefull of the moving parts.

That is how it would be diagnosed at a dealership.

sounds like an idler or tensioner pulley to me but you need to test. Guessing never turns out well.

Tech2,

Your right about the guessing. I already replaced both the idler and the tensioner pulley. That was a bad guess on my part but a cheap fix.

take the belt off and spin everything by hand in both directions, should be able to hear a bit of a growl or chirp on the bad 1