So I started a thread a couple of weeks ago regarding the major rattling sound coming from the front end f my brothers 05 Monte.
The sound is annoying as all hell and is really taking away from the fun of the car, especially since he is really just getting into modding it now. It sounds like a rattlebox POS.
At first I thought it may have been the hood. Some of u recommended to unscrew those rubber stopper things to help the hood from moving while latched.
While this did cure the rattling from my car, the hood was obviously not the cause in my bros car as I had expected.
I tightened the cai tray, it wasn't that. I tightened the cross bars, it wasn't those. It don't appear to be motor mounts either.

I'm thinking it may be something bigger, possibly something to do with the suspension. Maybe He needs bushings or something.
I kno it's hard to diagnose anything from this, but can u guys please give it a shot, and give it ur best educated guess on where and why the car is making this sound.

 

When does it rattle, over bumps? I would jack up the front end and make sure everythings tight.

It could also be a broken sway bar link or worn out sway bar bushing. The links are attached to the sway bar and control arm and the bushings are between the cradle and sway bar.

 

It rattles at ALL time. The car can be rolling at 10mph on a road surface smooth as glass, and u still hear that metal rattling.

Although it does get louder as the road gets bumpier.

 

Have you checked the heat shields on the exhaust? Those will rattle all the time. It could be a broken up converter as well

 

I had the heatshield rattle issue. You would know if that was the cause because it sounds like a tin can rattling when you rev the engine. Is it a metal rattle or plastic rattle?

My wifes Mazda3 has a rattle from the front that I can not figure out what it is. It kind of sounds like yours does. It almost sounds like it is coming from the front suspension. It rattles just when driving on an average road and really rattles if you hit any kind of crack or bump. Those Mazda3's though, I swear, you pop the hood and all you see is cheap plastic shields over everything.