I had the same problem too. It is coming from the right side of the hood (When you're sitting in the car). I figured it out as coming from the Air Intake Filter compartment. the latches are probably not tightened up so it rattles the compartment. I used bent the clips myself to tighten it up. There is now just a slight noise when you accelerate. I also noticed the car was sluggish initially when this latches were lose. But now the H3 picks up pretty well. I don't know what the Air Intake does, but making sure the compartment is tight makes a big difference.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MrCat:
When I accelerate from a stop or accelarate to pass, there is a fairly noticable loudness, rumble, and roughness from the engine. Once I ease back on the pedal to a constant speed it dissapears. After owning an Envoy, I didn't know if this was normal for an H3 as part of it's personality and ruggedness or not.
Can anyone lend any insight.
Thanks </div></BLOCKQUOTE>