I have a few dumb questions.
My XKR has developed a chirp on cold startup at 66k miles, it disappears after about 10 minutes of driving. However, I can also hear a squeak at about 4k rpm. I decided I am going to change the serpentine belt with the idler pulley and tensioner pulley. Should I change the belt tensioner as well? Does the 4.2 Supercharged engine use the same serpentine belt as the 4.0 N/A? What about the Supercharger belt and pulley, should I change that as well?

Looking in Rockauto, I can't tell which belt is for the supercharger and which one is the drive belt. The Goodyear Gatorbacks are now sold as Continental Elite Poly-V.

 

Is this the correct drive belt? https://www.rockauto.com/en/moreinfo...303&cc=1425844

Supercharger belt? https://www.rockauto.com/en/moreinfo...166&cc=1425844

Tensioner pulley? https://www.rockauto.com/en/moreinfo...955&cc=1425844

Idler pulley? https://www.rockauto.com/en/moreinfo...394&cc=1425844

I can't find the supercharger pulley. Also, after searching in the forum I now have a new question. Do I really need to remove the radiator hoses?

 

With the hood in the "service position" you can change the belts and pulleys without removing the upper hoses. It is tight but very doable.

 

I bet is is the idler pulley, sounds like the same thing I had once. Don't forget you can test that by slacking the belt and turning the idler pulley by hand. If she feels anything but smooth , replace her.

John

 

Loosen the belt pulley bolts before you take the belt off. It makes it a lot easier (Doh, been there).