yet another car noise question

[Lorax]

hey guys, noticed a weird noise on my 99 mercury sable. it is a metallic clicking coming from around the serpentine belt area. it's noticeable from park through 60mph or so, but once i get on the highway and cross 75mph and 2.5k rpm, it goes away until i restart the car. any ideas?

the noise started after i replaced my air filter, though that might not have anything to do with it.

 

[KIAman]

How loud is the clicking? Does the frequency change along with engine RPM or is it constant? When it goes away, does it stay away even back in park and idling?

 

[Lorax]

the frequency seems to change with the rpm. once it goes away, it seems to stay away until i restart the car.

 

[exdeath]

Idler pulley bearings can do that. What lube is left accumulates at the bottom and the bearing ticks and rattles, once it warms up and the lube spreads out it's quite for a while.

Try taking the belt off and turning and rocking every pulley (idlers and accessories) and see if any of them feel gritty or wobble.