I just put longtube headers on my 98 ss, and had a custom y-pipe made. I got it back and it is making a strange noise that is hard for me to explain. It doesnt sound like a rod bearing or main bearing. I thought it might be an exaust leak but everything seems to check out. It only makes the sound from 2400 rpms and up. Below 2400 rpms there is no noise. But it is definatly from underneath. If anyone has experienced something similar, or may know what this might be please help me out. And thanks in advance.

 

the y pipe might be rattling by the trans, try to get the front end up safely and start it, you should hear where its coming from, and you may need some sort of high temp rubber between what ever is making the noise, and the exhaust, or adjust a mounting hanger.

 

I thought it might be something like that to. I put it on a lift and that wasnt it. Thanks for the input though.

 

i think tha y pipe is tha problem