Hello all. New to the forums as you can see. I have just recently purchased a used 2006 Mazda 3i about a week and a half ago from a dealership. I am very satisfied with the car overall except for two things. One being the power steering pump whining while at idle. I have read and found that that is normal... Oh well. I dont remember it being so loud when I test drove it. The major concern I am having however is with a light rattling/grinding noise when accelerating between 1000 - 2000 RPMs. Speed doesnt matter. I can be crusing at 45 mph and very lightly press the gass and hear it, or at a dead stop and slowly accelerating. If I press it a little harder the sound goes away. It's consistent, and can be heard under the same circumstances whether the car is hot or cold. The car didnt make this noise before I bought it, ugh. Anyway, the car only makes this noise when in Drive or Reverse. I have tried to duplicate the sound when sitting still in Park or neutral, but have failed. Therefore, the rattling noise only occurs while the car is in gear and under load. I have read threads that it could be heat shields, or loose bolts, or the cats... Well I havent ruled those out or had them checked but it would seem that if that were the case it would make the same noise regardless of whether I was in gear or in park/neutral. Any ideas on what this could be? It's driving me nuts knowing I just bought this thing and already having issues with it. Thanks for your time and patience. Oh by the way, I managed to work in a 30 day 1000 mile powertrain warranty with the dealer.