Hi all.

Hope someone can help me. I have a 2007 RX8 six speed manual with 24ks on the clock. When the car has been given a good run and is hot but not over heating, when the car is pulling away from a standstill at low/ medium revs a muffled grinding / rumbling noise comes from under the car, if i raise the revs and go, it dissapears. this doesnt happen if the car is cold or been driven over short distances. could it be oil leakage on the clutch ? Or something more sinister.

Andy

 

Could be your heat shield above the catalytic converter, I briefly read about it last year that a screw or weld may come loose. Do you feel your cabin or the middle console significantly warm? You could jack up one side and check while your car is cool, otherwise, have your cat checked by the dealer. Sometimes, a bad cat wouldn't throw a CEL.

Addendum: check your oil level as well. There was a time I neglected adding oil and noticed rattles at mid-range during acceleration.

 

Had that problem and was solved simply by changing the rear dif fluid to synthetic. I used Red Line but Royal Purple works well also. Search and choose the recommended type.

 

I've been having a similar noise lately when the car has been warming up. I changed out trans/diff fluids and they didn't seem to help the sound(although I did noticed smoother shifts).

Yesterday I found that the heat shield around my exhaust header/manifold (part in front of the catalytic converter) was loose/rusted through, but I need to jack the car up to check out the area above my cat. See if any of those is loose or makes a rattle when you knock on it.