Recently, I've been hearing my toilet randomly sound like it's running. Sound lasts for 10 seconds or so and I see water dripping into bowl. I figure something needs to be changed? Is that something I can do?

Probably a bad flapper. Open the tank and put some red food coloring in the tank. If the bowl turns pink after a couple of minutes, the flapper is leaking. You didn't say what type of toilet and flappers can be specific, so make sure to get the right replacement. Check back if you need more help.

I agree with Ma0641 that you may have a bad flapper valve, If you don't have food coloring close the angle valve under the toilet tank remove the toilet tank lid mark the water level gave some time and check if the water is below the mark it indicates that flapper is bad, good luck.

John

My toilet randomly makes the sound of water running. It lasts for about 10 seconds, during which time water runs into the bowl, then stops. I feel like this is an easy fix but need an expert opinion. Thanks!

... and don't go to Home Depot and buy the Universal Flapper if you have a Kohler toilet! The Kohler flappers are different, and for me, were way high on another shelf where I never saw them til I made another really long trip back to the store. GRRR

Please don't start multiple threads on the same question. I've merged your threads.

The symptoms you describe indicate that the flapper seal isn't sealing properly, causing the tank to empty slowly. When the tank empties the float drops below the fill level. When that happens, the tank refills. Hence the noise you are hearing.

You should be able to replace the flapper yourself, depending on what the inside of the tank looks like. Take a picture of the inside of the tank and attach to a post here so we can help further.

remove the toilet tank lid mark the water level
Hi John,
That's to complicated for me and too much work.

I just hold the float down until the water flows over the overflow pipe.
Come back later. If the water is not still at the top of the overflow I have a leaking flapper. I don't even have to turn off the stop valve.

... and don't go to Home Depot and buy the Universal Flapper if you have a Kohler toilet! The Kohler flappers are different, and for me, were way high on another shelf where I never saw them til I made another really long trip back to the store. GRRR
Same for some Mansfield, American Standard and others. That's why you take the old one unless you are sure. PS, I made the same Kohler mistake.

An incorrectly connected refill tube can cause siphoning and short cycling...

An incorrectly connected refill tube can cause siphoning and short cycling...

Good point Mike45plus, check for correct placement of refill tube while the lid is off.