Toilet runing internittently

Thanks to anyone in advance that can help. I replaced my flapper abut 6 months ago, as I couldn't get the toilet to stop running. That solved the problem about 99%, but now every 20-30 minutes or so, it will run briefly, almost like it has a slow leak, and just needs to fill for a few seconds until its done. Is this a simple adjustment to the flapper? or somewhere else. I've played with it, but can't seem to get it to stop doing this.
Thanks.

If the flapper is still leaking, you should hear a dripping sound if the room is quiet enough. If you hear this sound, try pushing down on the flapper with a long screwdriver to hear if the dripping stops. You might need a different flapper or try adjusting the chain on this one. If the chain is too taut, it can prevent the flapper from sealing. If you replace it, try a Korky red flapper.

If the water is leaking into the overflow tube, that's a different issue and can be resolved by lowering the water level in your tank.

Make sure the refill tube isn't below the water level in the toilet. Better yet if it's on a clip above the overflow pipe.

#1 Did you replace the flapper with an identical flapper?

#2 If you purchased an inexpensive flapper it may need replacement.

Korky red or black flapper work very well compared to most others.

Also, run your finger around the "ring" where the flapper sits. I've seen these get fouled over the years and a good cleaning of them doesn't hurt.

Similiar problem with toilet refilling...

I am having a similiar problem....I replaced everything in the tank, however, every few seconds...the water kicks in for a second to refill the tank....

This might have been two separate problems, the flapper was the main one, however I've seen the valve "surge" due to a well pump stopping and basically it's the water hammer effect. Is the water close to the overflow tube, if not... never mind.

rancher

no it's not and I have the clip on the top of the overflow tube.....I don't see any water slipping past the flange stopper.....