Hey all,

I have a heavy lawnmower metallic buzzing sound when i step on the gas from 2000rpm - 3000rpm. any higher and the sound goes away. And it doesn't happen when i first start the car and drive. It takes about 5 minutes of driving before the noise starts to appear.

I thought it was an exhaust leak, so i take it to a shop. They couldn't find a leak anywhere and i asked if anything looked damage and they didn't see anything.

I used to have a different kind of resonance when my old OBX headers had a crack in one of the downpipes. When i had that problem, it would make those sounds when idle, when driving, etc. This is different in that it only happens after 5 minutes of driving and between certain rpm's.

What could be wrong with my car??

thanks for any and all help!

-Rob

 

Try checking the heat shield underneath the car, above the catalytic converter.

 

If it is the heatshield, how do i fix it? is it something i have to replace or just something knocked loose?

thanks

 

I'm having the same problem with my car. I was told to retorque the header bolts. I'm going to try that this weekend to see what happens. As for the heat shield, what would we look for and how would that cause the noise?

 

^ "As for the heat shield, what would we look for and how would that cause the noise?"

a loose heatshield that will rattle.

 

As for heat shield, sometimes the bolts rusted out and part of the metal shield is vibrating freely. Check to see if the whole shield is still screwed down tightly onto the bottom of the car.