Just thought I would share my recent trouble with my Caliber. About 2 weeks ago I noticed a small knocking/ringing sound (it sounded like a diesel engine). At first it would only make this sound when the car was running for an extended period of time, maybe 30 minutes+. Checked all the fluid levels and everything was fine. The sound was coming from the serpentine belt area but it was just too hard to tell what was making the sound. Took the car to Pep Boys and they said it was either a power steering pump or an alternator going bad. Took it to the dealer to see if it was covered by waranty, and I found out my waranty ran out at 36K (odometer is at 52K right now) . The mechanic told me it was gonna cost me $680 to put a new one in. I respectfully declined and took it to my father-in-law's mechanic who said he would do it for $250 INCLUDING labor! Just got the car back a few days ago and it sounds better than ever. I wish I would have recorded the sound on a video or something because it was absolutely HORRIBLE. If anyone has any insight as to why an alternator would wear out at 52K miles, please inform me. And if anyone thinks they have the same problem, send me a video w/sound so i can try and compare it to my sound. Thanks!