In my 08 X, I hear a slight rattle (noise, whatevr... hard sound to explain) at the peak of the rpm's height, right before it drops to switch gears.....it only happens under hard acceleration and high rpm ranges (5000+). It comes and goes so I don't know if its worth a dealer trip.

I don't have any loss of power while accelerating, no slippage in gears, its just this slight annoying sound.

Anyone else know wtf it is? I had my tranny flushed and ecu updated 2k ago, still comes and goes. Any info would be appreciated

 

its the powaaaaa

 

hard to tell without hearing it first hand, but just could be a normal rattle since you are under hard acceleration at a high rpm. But again, its something that is hard to diagnose when you can't hear it.

 

i have the same thingi think its a heat sheild or something nuthing to worry about but it is annoying

 

i noticed the same exact thing on my 08 x as well. It's not loud (ie i can't hear it if the stereo is on) but doesn't sound right.

 

I would like to say it's normal. For me my 3rd gear slams in when i accelerate very hard.

 

What G do u have? A 37 with 7AT? I don't have any slamming of gears (knock on wood).... it doesn't sound like anything is grinding which would indicate a cooked tranny, but I guess its some consolation others have it too....

 

07X here, and same symtom during shifts. I've had other cars that made quite a bit of noise when the AT lets up to shift during hard accelleration too, so I assumed this was normal.

 

 

I drove a loaner 2010 g37x and it had the same noise during hard acceleration... so it seems like its normal.

 

Yeap, same here as well. sounds like it's coming from the passenger side, by where the seatbelt meets the door or something

 

I get the same thing. I have an 08 G35S Sedan, i seems it does it more when the car is cold. That same raspy sound you are hearing. I haven't had a chance to get underneath the car and check the heat shields but it sounds like that might be it.

 

heat shields. loose cat honeycombs. loose bolt or screw. window rattling inside door. change in the center console. acorn stuck in windshield cowling. weld slag trapped in exhaust pipe.

could be anything. just start tightening and eliminating things until it goes away.

 

As long as its not engine troubles or tranny probs, I can live with it.... it comes and goes

 

^^ Hopefully it is just some annoying nuisance issue as others have said; but do make sure what you are hearing is not detonation. Are you using a quality brand of premium in your car?