Everybody knows that you should change your oil and rotate your tires on a regular basis (I hope). Some people even are aware that you should also change other fluids in your vehicle at specified intervals as well. However there are lots of moving parts in your vehicle that should be checked and/ or changed regularly or semi regularly as well. The most important one I want to talk about is timing belts!!
You may ask, what is a timing belt and what does it do?
This is a timing belt. The "teeth" on the inside connect with sprockets on the camshaft and crankshaft of your engine. This is what keeps all of the valves inside of your engine moving up and down at the correct time. They call this "valve timing". Valve timing is crucial to your vehicle running smoothly and properly.
If your timing belt breaks it can be catastrophic for your engine. Below is an animation of a properly running engine. Your engine has 2 sets of valves, intake and exhaust valves. When the piston goes down it creates a vacuum in the cylinder to suck in the air fuel mixture. The piston goes down as the intake valve opens. Intake valves traditionally open to allow air/ fuel mixture into the combustion chamber. When the piston reaches the bottom of its travel, the intake valve closes so as the piston comes up the air fuel mixture can be compressed. Once the piston reaches the top and the air fuel mixture is compressed your spark plug will fire igniting the compressed air/ fuel mixture and expanding rapidly pushing your piston back down.
Once the piston is pushed back down to the bottom of its travel the exhaust valve will open, and as the piston comes back up it pushes the exhaust gases out of the exhaust valve, where it will leave the combustion chamber and be pushed out through your exhaust system.
If the timing belt breaks the camshaft(s) that open and close your valves stop turning. Often leaving at least one set of valves in the open position, while your crankshaft continues to move your pistons up and down. Many newer cars have interference fit engines. What this means is that there isn't enough clearance between open valves and pistons at the top of their travel. So your pistons continue to move up and down smashing into open valves. This happens at incredibly high speeds even at idle. At idle a piston moves up and down between 16 and 33 times a second. Often what will happen when a timing belt breaks is that the valves will bend or break. This is where the catastrophic part comes in. If the valves bend even the slightest bit, the cylinder head will have to be removed and checked for damage, and at minimum the bent valves will have to be replaced along with gaskets associated with taking the cylinder heads off. This is why properly maintained timing belts are so important.
I hope this has been informative!