97" gsr swap in 93hatch, never heard the noise before just started not to long ago, but the noise sounds like when u are underload going uphill except u can hear it on flat ground and only under 2000rpm, the motor has not lost power it actually feels strong, Thought it might be valve adjmt, so i did it, and it needed it but the noise didn't quite go away, motor feels stronger after the valve adjm. The motor only has about 75thousand miles and always change the fluids on time never miss. so if anybody can help?