Tapping, clicking, ticking, rattling, knocking — whatever you may call it, it’s something you do not want to hear coming from your engine. What is engine tapping? A clicking or tapping sound coming from your engine that gets louder as you crank the engine is most likely “tappet” or upper valvetrain noise, which can be caused by a number of issues including low oil pressure, excessive valve lash, or worn or damaged parts. It could mean a number of things that will not always be easy to diagnose. Fortunately, it could be a simple problem you can fix yourself so it’s best to really know what is engine tapping, because you’ll never know you may not need to go to a mechanic and do the repair yourself. We will learn all about what is engine tapping in this article.