Today, I went to OC Nissan Irvine to have my oil changed and everything went well. I leave to drive to Newport Hills to fill up with some race gas for a change and did a roll-on starting in 2nd gear onto the highway. When I shifted to third, there was a loud pop; almost like the soft pops that come from an FI exhaust on decel but much louder, and it sounded like it was from in the cabin. The clutch was fully depressed on each shift.
The clutch felt fine and nothing changed in the car, so I drove gently for a little while and got gas. On the way home, I did a quick 0-60 sprint and again, another pop from 1st to 2nd this time.
I checked the clutch fluid and it was normal, I didn't smell anything burning, there were no additional noises from the drivetrain, and the clutch felt normal. Do you all have any ideas what might be happening? On the way to work and to OC Nissan, I did the same type of shifting and it was perfectly fine.
I'm going to check the sway bars and look for anything under the car now that it's parked and will update.
TIA!