[Lakitu]

I have this issue, directly related to possibly 4 things: clutch, idle, gear oil, and AC

1. Cold start the car with AC off = gentle knocking sound
2. Press clutch = noise goes away
3. Release clutch = gentle knocking noise returns
4. Turn on AC = noise increases in loudness
5. Press clutch = noise goes away
6. turn off AC = noise returns to gentle knocking
7. Drive car through all gears = can't hear noise if its there (car exhaust probably masking the sound)

No matter how long I drive the car for the noise persists, as long as upwards 3 hours at stops and in idle.

It sounds like ice cubes sloshing around in a huge cup.

Was told this sound is completely normal specifically if you have Motul300 in the transmission, so I've been ignoring it for about 10K miles. Someone told me that the input gear is smacking the teeth on the idler gear because Motul300 is apparently much thinner than OEM gear oil. No associated issues with shifting or driving. Car is as smooth as butter. Just noisy.

It is a bit concerning as it is very audible from outside. It makes me not want to run the AC at all and suffer. I might switch back to OEM gear oil to experiment and see if it goes away.