Hey guys... 04 MT RX8 w/ 102,5xx miles. Few days ago I noticed a weird rattling noise coming from either the engine bay ... or sometimes kinda sounds like its coming from underneath. Sounds like its coming from the passenger side.

Noise comes while accelerating mostly but I've noticed it while coasting too. Its not the Marbles in a Can symptom. I had that before and problem went away when they replaced my engine core at 86,000 miles.

Take a listen... any ideas? THX greatly in advance!

http://www.youtube.com/watch?v=WWbtFTJMBaw

 

First thing I would check are the fuel and brake hard lines running under the car on the driver's side.
You'll see the 4 black lines running parallel towards the rear.
See if one of those holders broke off and the lines are tapping against the underside.

 

Does it sound like something is being sprayed, do u notice it at high revs

 

Pretty useless video..
Probably your exhaust touching a cross-brace.

 

Damn... I feel dumb for overlooking the obvious first.

 

Don't feel dumb.

It's almost always something simple, though.

 

Hum I have new reman with 2500 miles on it and it make similar rattle. I suspect maybe the motor mount on the exhaust side is peter'ing out. lol... Engine shakes a tiny bit. I like shake so to me it's a feature lol. There is a new part out if it turns out you need to replace that is better part.

 

might be broken piece in your cat

 

The best I can do with a camera phone....

Just wanted to help describe the rattling noise its making. I suspected motor mounts when I first heard it a few days ago so I searched a bit on it... but wanted to get different opinions. I havent had the chance to jack her up and get under there...

Might end up taking it in to the dealer see what they say...

 

I was at about 3.5k rpms... (in the video) i accelerated... then let off... then accelerated again... about 3x and every time I accelerate you can hear the rattle.