Well, no one on other sites seem to be able to help me with this, but I figure people with similar cars can.

I drive a 1997 Eclipse GS 2.0 N/A.

I just notice a lot that whenever I throttle hard enough, as soon as the RPM's hit 3000+ under acceleration, I start hearing this very loud whistling noise, which gets louder and louder, and then at about 5000 RPM it sounds like a squirting/squealing noise.

I have no idea what the hell this is, someone claims it could be a leak in my exhaust manifold. I don't have the proper tools to check this for myself. I figure that if this is the problem, it might also explain why my engine gets so hot so easily, also why it runs so sluggish.

Please give me some suggestions or tell me about your similar experiences so I can get this solved. I get my first paycheck from my new job on Friday and I'm really excited because now I actually have the money to go buy replacement/overhauling parts. :)

Could it possibly be one of your belts? MY PS belt squeals under hard acceleration.

Couldn't be. I replaced a belt and it stopped making a squealing noise at idle and low RPM, but I mean this one really sounds like a whistle.

Actually, kind of sounds reminiscent of a really loud version of someone who doesn't know how to whistle, and they just blow air through a very small hole in their mouth.

PS - If it is possibly the timing belt... then who knows. However, I don't know how it could make a spurting sound. Also, it seems that the car has much less throttle response when I'm hearing this sound.

Last time I heard that kind of noise, it was a bearing getting ready to go out on my alternator (I removed it, took it to an Autozone for testing. 5 seconds after they started running it on their dyno tester, the bearings exploded, and shattered the case).
IMO, check your bearings on things that are run by a belt. It could be any number of them, or a combination of multiple bearings (AC pump, Power steering pump, idler pulley for those two things, alternator, pulley and tensioner pulley on timing belt, and water pump).
Not saying those are the problem, but I would check them.

I have a feeling the power steering is going too, because whenever I turn the wheel as far as it can go (only when I'm reversing...?) it makes this extremely loud screeching noise and everyone stares.

tighten the ps belt.

i just had the same problem with my 97 RS, and i replaced the muffler with one of those cheap cherry bombs from autozone, i think$20 and it quit

Awesome, I might do that too to see if it fixes the problem. That actually sounds quite reasonable, because the whistling happens even if the car isn't moving, as long as it's revved higher than normal.

I hear those Cherrybombs sound nice too. True?

i think mine sounds great, and for the price you cant beat it.

Does it fix the problem or just drown out the whistling sound? ;)

Is the vacuum line attached to the PCV valve? lol

on mine it took out the whistling all together and i dont know what your talking about that pvc valve

PCV (NOT PVC)= Positive Crancase Ventilation. It sucks air out of the valve cover. If the vaccum line that goes to it leaks it'll whistle. Any loose vaccum line would whistle for that matter.

its the muffler mine did the same thing until I replaced the stocker with my Magnaflow. now instead of the whistle I've got a supernice tone with a great looking muffler.

Are you sure that the "supernice tone" you speak of just doesn't override the whsitle? lol

Yes, because unlike almost every other Tuner in the world My MagnaFlow Wasn't cheap, and is not one of the obnoxious loud mufflers. Its bold when I'm on the throttle and quiet when I'm not. It aint no cheapie. Replacing the Stock muffler removes the whistle.