... that is the question...
I hear a rattle at 1400-1500 rpms gets harder to hear (I think) when the car is warmer.
sounds kinda like detonation as I have heard my car detonate, I heard it detonate over the weekend (gas....) and this is almost like it but it sounds "lower" on the motor (hear it bouncing off the ground more so) and is a bit higher pitched than the normal detonation.
I took it down from 23 deg timing to 21 deg with a different tune I have and same noise same time same amt of noise for the issue I am talking about. My normal detonation went away but the noise I mentioned above did not change.
I am thinking its not detonation, but... not sure how to rule it out other than leave it at 21 degrees and put in some race gas
to ensure I have enough octane for the timing level.
It happens under normal acceleration. On WOT I hear NOTHING all seems fine.
Other thoughts are a cat going bad or something loose rattling, but I see nothing loose.
Any tips/tricks ideas etc? I want this noise at least figured out.