Regular or high octane?

When was its last good tune up? There could be something else going on as you normally won’t hear anything unless you got really poor quality fuel. But if you want try a few tanks of higher octane and see if it goes away, it not going to hurt anything.

Thank you very much, for detailed answer. Have a nice day.

I agree, sounds like a bad knock sensor. If your check engine light is on visit your local auto parts store and have them scan the computer for trouble codes. Most stores will do it for free. If you get a knock sensor code, there you go. Hope that helps! Jim

Thanks ,for your help

You're welcome. Glad to help! Jim