KittyPaws

I changed my drive belts early last week, and tightened the one that goes to the alternator a little too much (figured this out because of the rough growling noise engine was making). After driving for a day or so, I loosened it up quite a bit. This seemed to fix the noise problem, so I thought everything was ok. This morning on the way to work, a terrible, very loud noise started coming from my engine, but only when rpms reached 2000 and above. The noise is kind of low pitched, growling, but seems to be a little cyclic, and is WAY louder than the noise previously mentioned. I guess it could be a grinding noise, although I don't want to be too quick to call it grinding. While at a stoplight, I decided to test the noise out a bit since there wasn't any road noise to interfere. When idling at about 750rpm car sounds normal. I revved it up past 2k, and the noise suddenly started right at the 2k mark. I'm not sure if this new noise is related to the drive belts, and I'm going to hop under the hood after work tonight, but thought I'd ask for suggestions. I'm saving up for an STI, and can't afford big money in car repairs or a new car yet So I'm hoping it's something simple, or that I can fix myself. Any thoughts? Much appreciated!!