I need help diagnosing this problem I have been experiencing a lot lately.
Situation: When I drive normally or aggressively, between the rpm ranges of 2.5-3.5 there is a loud noise coming from the engine which resembles the sounds of a train letting off steam. Someone in a forum once suggested this to be a Power Steering Pump which may need a new seal kit or replacement. Hopefully I could get this fix soon.

Here is a Video I shot, Please help if possible.
http://www.youtube.com/watch?v=CsIj3rpGeOM


Notes: Sorry if the camera shakes a lot, PA seem to have an infinite amount of turns and pumps on small highways.

 

Hey, I watched the whole Video, and i'm a little stumped. It was really hard to hear the exact sound, but I think I heard it pretty good a few times. It does not seem to "whine" like a power steering pump generally does, unless i'm just not hearing it correctly.

Can you get it to duplicate the noise while the car is parked, and you just free rev it? If so, I would pop the hood, and have someone rev the engine between 2.5 and 3.5 RPM, and listen for where the noise is coming from. If you use a really large screw driver, and put the tip on things you think are making the noise (obviously make sure you are careful and don't put it to close to moving parts) then put your ear at the other end of the screw driver (the plastic end) you may be able to pin point where the noise is coming from exactly.

Possibilities I would look at more:

-Power Steering Pump
-Water Pump (when the water pump in my truck went, it did not make a whining noise, but it did make a weird "thumping" noise because the bearing went out, and it was letting pully wabble)
-Alternator (this may whine if the bearing in your alternator is bad)
-Serpentine Belt (maybe try putting some belt dressing on it and see if that stops it)

If you can at least pin point the noise to coming from the passenger side of the engine bay, then I would say it is most likely one of the things I just mentioned.

 

Yea I don't really know what the problem is, it just makes that train sound uuuuuuuuuuuuuuuuuuuuuuuunnnnnnnnn(un in uno) for a bit in highways, but sometimes in hills it does that like forever, it was just annoying, I went to a couple of shops to take a look, yet no one found the problem, they said to wait it out.
It is true that it sounds like it was louder in the passenger side, and I tried to rev the engine around 2.5-3.5 rpm and it sound normal and good. I even played with it above and below. There wasn't any problems that could be found while parked. This sound only comes out during acceleration and while moving, someone told me that it could be just air trying to escape, and the problem will show itself when it is ready to come out. I would try to get some belt dressing on the serpentine to try that, but I could heard the belt when I accelerate even before the sound, the shop people said the belt was normal. Thanks for watching the vid, hopefully the sound was loud enough to hear. I'm still trying to get a day off to bring it to a chevy dealer or the place I bought the car from, and pay overprice parts and labor if it must come to that.

 

find a tranny shop and have them look at every thing with the tranny it to me sounds like the tranny pump in side the tranny is getting ready to go. the same thing happend to my truck before the tranny blew up the tranny pump stoped working it started to make a funny noise and hard to accelerat to get to normal speeds like 35-45 mph

 

Well today I finally figured it out, This sound was caused by pressure, at least that is what I think. Although the video was removed, if you heard the vid before, it isn't the trans. Though the trans was having a hell of a time shifting, and seem to be going bad. Today me and my friends started the dual exhaust installation. We cut down the stock exhaust, and of course we had to test it out without a muffler cause it is just fun. But after installing a 25 dollar ebay muffler, we took it for a spin, and no more whine. So in theory I think it was getting too much back pressure from the air intake or something and because of back pressure it caused something to whine. BUT I dunno what it actually damaged. SO people with whining problems similar to my description Get one of those cherry bombs, glass packs, or cheap ebay mufflers and test out your luck.