Every 10 minutes a whooshing noise comes from our toilet (its annoying) the noise last 5 seconds. We built the house in 2005, so its fairly new.

When I take off the tank lid and look, there are small bubbles coming from the left side of tank at the water inlet or entrance, then the rubber ball goes down slightly for 5 seconds... this causing the noise as well.

I've taken apart the left side, but am unable to remove the plastic inlet base plug, there is also black paint stuff around it.

Is it necessary to replace this plastic cap, or should I just put back together and see if its fixed...

Thanks,
johnjaha