I have a noise coming from the passenger side of the engine on start up, kinda sound like a cricket but not as high pitched. Seems to go in a rhythm with the turning of the belt, it seems to go away after the car has warmed up. Could this be the water pump or something?

 

How many miles on it,
I would probably just replace it (for the cost)
And then inspect all the pulleys ,water pump,altenator and tensioner etc in the process.
It probably stretched and just the load from the altenator could be making it chirp.

 

The belt isn't even a year old yet, but the car has 63k. It doesn't really sound like a belt chirp tho, but i am going to check that out anyway.

 

mine does the same its the balt and moister on the belt on cold start up

 

Which of these is more likley to cause a noise like this, the tensioner pulley or the idler pulley? I have done a bunch of searching and narrowed it down to these 2 things.
The tensioner is 119 on gmpartsdirect, thats kind of an expensive part to be throwing at the car, the idler pulley is around 30 i think.

Will the screwdriver to the ear work for locating this noise? seems kind of dangerous with the spinning of the belt to do this.

 

mine stopped after i greased up the ideler pulley