[catbirds galaxie]

I think I have a bad idler pulley. Started chirping this morning. After lunch I go outside to see what exactly is making the noise and of course it’s quiet as can be.
I turned off the engine and physically check the idler pulley and it does have some slop. Looks kinda rough too.
I think I’ll go ahead and get a new tensioner and belt too.

It has 2004 Mustang GT heads. Do I get a Thunderbird or Mustang idler pulley?

 

[theterminator93]

They're the same. I would order the SKU for the MN12 though, let the corporate overlords see what car I'm putting it on!

 

[T6Rocket]

The first one to go is usually the tensioner pulley. I would replace the tensioner if you have not, and that idler pulley. Get Motorcraft for both, don't want to end up with a plastic idler pulley.

Al

 

[catbirds galaxie]

I got a Gates complete kit. Nice steel pulleys too. I was expecting plastic.
Both pulleys were shot. Nice and quiet now.