Weird Noise When Warm

[T_love]

My car recently started making this loud rattling noise when accelerating. It rattles faster with increase in RPMs and it does the same thing for each gear. This only happens when the car has fully warmed up and its warm/hot outside. The best way i can describe it is that its kinda like the sound you make if you hold something like paper against a fan.Or better yet, the sound that bad CVs make when you turn, but only increasing in relation to the RPMs . This only happens when i'm in gear and it doesn't happen in neutral, whether the car is moving or standing still. I'm thinking it has something to do with the transmission but i'm praying that its not that or the engine coz this is my daily driver.

Has anybody experienced anything like this or have any idea what this might be. Its really frustrating and embarrasing. Thanks for any help.

[kouki-gymkhana]

Is it difficult to put into gear? Did you change the pilot bearing when you did the swap? How about the throwout bearing? Give us a little bit more info so we can get a better sense of what might be causing the problem.

[T_love]

Its not really difficult to put into gear and i did not change any of the bearings. I took a little drive earlier to try and pinpoint where the noise is coming from. From what i could tell, over the loud exhaust and other noises, it sounds like the sound is coming from the rear of the car. I haven't touched the diff, and the entire driveshaft is new. The car has coilovers so it is dropped quite a bit. I was thinking it might be the diff but i don't know if that's what it does when its dying. I also don't understand why this only happens when accelerating.

[NISMO_RB25]

I take no responsibility for anything bad that happens to you if you try this, but here is an idea.

Put the car up on 4 jackstands and strap it to something stable, such as a tree.

let the car warm up, put it in a low gear and give it some gas. Get a budy to listen at the back of the car to see if they can find out what it is.

I know this sounds kind of crazy, but I did this when i was first working on my car and got the speedo up to 30 or so mph without flying off the jackstands.

[T_love]

I was actually thinking about raising the rear and doing the same thing, sounds kinda dangerous though.

[Slo_240sx]

When you do this just make sure the jackstands are under the control arms. If not then the axle angle will be way off and tear the boots apart once to step on the gas. More than likely you have bad U-joints. Take off the driveshaft and rotate the yokes. If you can feel a sluggishness or a bind than its bad. I wouldn't be surprised if it were a carrier bearing either if you decided to retain it like I did. U joints, carrier bearing or rear end subframe bushings is what I'm gonna condemn.-Alex