water pump

Hello everyone! My 09 has 145k miles and makes a rattling noise that gets louder with time. Each time it does that sound (first time @ +/- 30k miles) my Toyota dealer changed either the water pump or the alternator and it fixed the problem for a few months. Then, the rattle comes back. So...

hey people, I've posted this a few places but i assume they're dead threads. or no one likes me haha I'm think my problem sound is coming from one of the pulleys, possibly the water pump. can anyone make a guess from the description below. I've got this squealing sound coming from the engine...