at around 2500 rpms it starts to get loud and then after that it sounds normal again. not sure what would cause the loud noise. warm or cold it still does it, im afraid to actually romp on it cuz of the noise so i putt my way onto the highway. any thought would help, oh yea any gear too, anywhere from 20mph to whatever i go to.

 

To start with, try this:
With a cold engine, and the motor off, try to spin the cooling fan. If it does not spin easily, then the clutch is going bad. If it tests good, then we'll go from there and look for other causes.

 

I agree start with this test and let us know the results!!!

 

yea thats already a prob cuz i tryed it and it needs to be changed. i think it might just be the engine cuz my friends mom's blazer does the same thing at 2500 rpm but just a little quiter and she has a new engine. so idk

 

Then I would change the clutch on the fan, it seems like from what you say that its stuck or sticking!!!!

 

lol mine dose the same thing, alot of kids think i have a v8 becasue it sonds so loud and beastly, and its the clutch, well wheni turn the heater or ac on you can hear it, or it will click every once in a while

 

Yup, it's the fan clutch. I've deen some aftermarket ones that are like that from new because the clutch is to tight and won't free wheel.

 

ok why only at 2500 rpm though, this is what i don't understand about it.

 

If it were my fan clutch and it had tested as being bad, I would just replace it. Other than just curiosity, why spend my time wondering why it acted the way it did? We're not saying that the fan is the only source of the noise, but until it's replaced there's no way of knowing if there's another source or not.

 

well of course im gonna be curious as to why. and yes im gonna replace it. im new to owning one these blazers and not use to all the new probs that occur. i had a 93 chevy cavalier z24 and got use to those probs, this is a whole new ball game, but some parts are cheaper go figure.