I have a 1996 blazer 4x4 4.3, when driving low speeds, it is quite but when I get up over 55 I start getting loud noise coming from the front end. Noise sounds like roaring noise, I have had the tires changed and still the same noise, with street tires not off road tires. Also sounds like there is water in the dash somewhere, but no leak and no water inside.

 

Any better idea than just the front end somewhere? outside or inside engine compartment?

 

im not sure its the same but my 2000 blazer was making a strange noise when i was on the highway and gave a little gas it sounded kinda like roaring in engine for a week or so then the cat converter started rattling and i had it replaced and both noises are gone now

 

wheel bearing?

 

2x on the wheel bearing and maybe a heater core plugged or something on the water sound in the dash, lots of info on here for both common problems