Definitely an unusual noise. I was thinking it could be a broken damper or 2. Or like the previous post a bad or weak valve spring. Does it chatter in the driveway if u rev it up? If so remove the valve covers and try revving the motor up and see which valve springs are making the noise
Last edited by cadillacdave1; 01-13-2013 at 12:46 AM.
Reason: add to post