Why is my transmission making a clucking noise while idling?

I have a 98 Honda civic hx with manual transmission. The transmission is making a clucking noise while idling, Its not overly loud but you can hear it clearly. When I put the clutch in the noise stops. And it also makes like a grinding noise in gears 1-3 but not 4 or 5. It is the most loud when I'm in 1st gear. The grinding noise is on and off. But the clucking noise is constant whether while idling cold or hot. The transmission has no grinds or pop outs ever and shifts good.

Please tell me what might be wrong with my transmission!

Also don't forget to search this on Google.

Tough to say from the facts above. I would have a friend or a professional take a look at it.