kitchen sink mystery leaking

well, my problem started about 2 month ago. one night i went to the kitchen to find water all over the floor coming from under the kitchen sink. the water was really really steadily pouring out from both the p-trap area and the other sink with the disposal in it. i shut the water valve off and cleaned up the water and went to bed. the next day i turned the water back on to see if i could find the leak but nothing was leaking. so all was well until about a month later when the same thing happened. this time i turned the water back on right after i cleaned up all the water and it had stopped leaking.... then tonight it did it again so i did the same thing and again, no leaking. this happens all of a sudden, it's been hours since any water has been run in those sinks. it just seems to start for no reason but stops when i turn the water valve off under the sink and back on again... what is happening???

If the leak is coming from the p-trap, turning your supplies off will not stop the leak from occurring. The supplies provide water to the faucet. So, if you turn the supplies off, the leak would continue coming out of the trap until the water in the trap has drained to below the hole/exit point.

I'm no pro, but try putting a bucket under the trap and turn the faucet on, and allow the water to run. This will ensure the trap is full of water so you can see what's going on. Wiggle the trap around with the water running and see if you see any leaks.

This is a case where you have to get on your back, wiggle your shoulders inside the cabinet, and start inspecting with a flashlight and feeling everything with your hands. Look for something which is wet!

If the faucet is on a flexible tube that extends out from its housing, check that its connection isnt leaking. When you shut the water off and on you may also be fiddling around with the faucet, reseating it in a position that doesnt leak, but after some casual use it might open up again.

To quote a couple of frequent posters...don't ask me how I know.

leak

You may have something, such as a water softener drain, connected to your sink's drain and when it regenerates it overflows, or leaks under the sink, for some reason.

How about the dishwasher? Was it running anytime befo you found the water?

the dishwasher was ran about 12 hours before, and there is a reverse osmosis system hooked up (professionally) under the sink. this is no small leak. i'm talking about 2 gallons a minute leaking out until i shut the water off. then when i turn it back on... the leak has stopped.

I would put a pressure gauge somewhere on my water lines.
I bet the pressure is climbing and causing the leak.