Alternator belt broke again (2007 Kia Rio)

A while ago my alternator belt broke, and it took the alternator with it by getting sucked inside of it. Looking at the belts they all looked super old so i replaced all 3 of the drive belts as well as the alternator. Things were fine for a while but I did start hearing belt squealing and then the alternator belt broke AGAIN. This can’t be a coincidence right? I assume there is something wrong causing the belt to wear out faster then it should. So I went ahead and already replaced the belt again and things seem OK again, but I’m also a bit afraid of driving the car too much as the belt may be destined to break again. I’m thinking I may just take it somewhere and have a professional figure it out but I want to hear some other opinions first. The car isn’t exactly worth a ton so I’m not planning on spending tons on fixing it (hence why I’ve been fixing it myself mostly). Also the belt seemed to be split down the middle and I’m not sure if that’s how a belt normally goes.

Most likely a pulley needs to be replaced. Run the motor and look at the pulleys on that belt, you might see one wobble a little bit, that’s the one that needs replacing. I don’t know if your car has it but the automatic tensioner could be bad as well.

With engine stopped and the belt off, rotate and jiggle every pulley that belt rides over. Somewhere there’s excess friction or play.

Less likely: one of the pulleys is not in the same plane as the rest.

If there is a tensioner pulley running on the alternator belt, make sure it spins freely and straight.

If the battery on this Rio is old and tired, you may be trying to draw a lot of current from the alternator trying to charge it. Thst will put a load on the belt as well as any high power accessories like amplifiers for sub woofers.

The squealing noise was the belt slipping over a drive pulley or idler that was binding up. One of the belt-driven accessories, or perhaps the idler or tensioner has defective bearings, and will bind up under load (meaning when a fully tensioned belt is installed) but it may spin freely by hand when the belt is removed.

Also, unrelated to this particular problem, I assume you are aware that this is an interference engine with a rubber timing belt. If you don’t know if/when that was replaced, I would have it changed too–together with the timing belt tensioner and idler.

On this engine, the water pump is driven by the accessory belt, and if it has over 100,000 miles on it, you should change that too.