when i am in 1st or 2nd gear and i am deaccelerating, especially when i am around 2500 rpms or under i hear a loud rattleing sound coming from under my car. its sounds like a bolt in a bucket.
it does not happen if i have the clutch in, but with the clutch engaged in 1st or 2nd i still hear the sound. it doesnt happen in 3rd or 4th or when i am downshifting so i am wondering if i have a problem with my transmission? please help me out on this.

 

That could be several different things. Best thing to do is take to someone for diagnosis.

Could be exhaust rattle, clutch problem, flywheel problem, wastegate problem, the list goes on.

 

when the car is stood do you get the noise?? if yes and it goes away when the clutch peddle is pressed then its the thrust bearing on the clutch other one to look for is the tensioner on the serpentine/fan belt

 

i think its the same noise when the car is standing still, but a lot quieter, i think that maybe sumthing else tho :/

 

you say its when your down shifting. does it sound like it might be something in the exhaust. what they said may be right but I had something similar and it turned out to be the cat going bad. if you take your car to an autozone and have them scan it, it will tell you catyilatic inefficantiy or someting like that. that should tell the story.

 

sounds like the flywheel but im not sure iv had something happen like that but after a few times my flywheel lock ring came off and my starter just sat there and spun so yea...

 

thank u all very much for the advice i will try not to drive it too much for the next 3 weeks until i can get it serviced

 

-yeah that catalitic converter can rattle loose and make a lot of noise.

-you would think a throwout bearing or thrust bearing would make more of a whining noise and in every gear rather than just 1st and 2nd.

-the clutch disc could have deteriorated and had some pieces broken off. and those could be rattling around.

-some exhaust bolts could be coming loose.


thats all i can guess. good luck man. i hate when this crap happens.