What does a Camshaft do?

What does a Camshaft do? Welcome to Mercie J Auto Care, where compassion and craftsmanship come together. I'm Rick Smith, master certified technician. First of all, this is a camshaft. This is out of a Hyundai. I don’t remember what year and what model it is, but it’s a four-cylinder dual overhead cam which means it has two of these above the head (overhead cam) duel as in two. We used to joke when I was in school that a camshaft, the technical term is a bumpy stick. If you look at it, it’s got all of these little things that we call lobes and they’re shaped kind of like an egg if you looked at them on end. So as this spins, this lobe pushes on (depending on the type of engine) it can push on a lifter and a pushrod or it can push on a rocker arm. Whatever it pushes on ultimately what it’s doing is it’s pushing open and close the valve. The valve is like an ink pen, the spring where you push it open and closed. Then we also have a gear on there that is what’s called a cam phaser and so it can go bad as well. Basically the camshaft is timed for the position of the pistons. That’s why we have what are called timing chain or timing belts that run the camshaft. I hope that gives you a little basic explanation of what a camshaft is. Until next time, safe travels and blessings to you.