My mechanic took off both belts off my 05 STR and the squeak went away...Put them back on and the noise returned...I originally replaced my S/C belt with whatever OEM Jaguar uses...My mechanic recommends redoing both the S/C belt and the accessory belt since they're fairly cheap...Rock auto has many brands, which do you guys recommend?

RoadMax, Dayco, Goodyear, Gates, AC Delco or Flennor?

 

My guess is you have a pulley going bad causing the squeak, I would advise getting a mechanic stethoscope and check the idler and tensioner pulleys for an abnormal bearing noise.

I would use Jaguar belts, they are not much more than aftermarket.

 

I think you know this but the 2005 STR has a TSB for belt squeak. It requires some pulley changes and a different belt.

Do you have the upgraded double belt?? It will have ribs on both sides. The standard one is only ribbed on one side.

So you might have a bad pulley but you could also just have some belt slip from the one sided belt.
.
.
.

 

I just did the belts on my 2005 styper. All my pullies are still stock and never been replaced nor did they every have any squeal. i went with Gatorback belts for both. If you need the part number for the belts, I can get them for you. If i remember I believe I paid about $60 for both belts, around 30 each.

 

I have the two sided belt, tbird...03xtype, I may just replace the idlers and tensioner and put on new belts...styper2003, that would be great if you could get the part numbers...

 

+1
Also have him take a close look at the crank pulley. Sometimes the damper delaminates and you get what sounds like a belt squeal for awhile (6 mo. to a year or more, in my case) and eventually it starts chewing belts (like my 03 S-Type) or just tossing them off undamaged (like my Excursion Dsl)
On the Ex, it was all wobbly and pretty obvious. On the S-type, not so much. I had a replacement Auto-Zone alternator that had been on about a year, and could've sworn its pulley was misaligned...to the point of convincing the AutoZoners to exchange it.....no joy with the replacement, either....finally gave up and took it to Motorcarman, IIRC he had it on-hand two days before he found it. Very benign failure.

 

If I'm not mistaken Gatorback belts are only made single sided not double which is needed for the updated type. Please correct me if I'm wrong ....

 

Correct, both the Goodyear belts I got were one sided. Also remember all my pullies as stock and and never been updated, since they have not squealed yet.

I looked up my receipts for you.

Serpentine Belt Goodyear 4060910 ---$19 ebay.
Supercharger belt Goodyear 4080521 ---- $32 rock auto.

hope that help.

 

Yeah, I got excited getting the 05 gatorback p/n, but I forgot that the older 05s were still single sided...I have a double sided so it won't work...

I had a squeaky belt before, it got so loud under load...The sound now is an annoying chirp, doesn't really get louder under load...Sounds like it's probably a pulley...

 

Anyone know if the replacement idler pulley includes a new bearing?

 

the pulley and bearing is one unit. once the belt is off if you spin it by hand with a stethoscope you will hear right away if its bad, if its real bad you will start to feel some play in it.