Hello, my name is Thayre Hawkins, owner of Auto Alternative.
I want to talk to you today about timing belts. Here I have a mockup of a timing belt; how it’s arranged.
Right here is your cam gear, down here is your crank gear, we have a water pump, timing belt tensioner, timing belt idlers.
The job of your timing belt is to keep your cam, your crank in time together to have a controlled explosion, the more control that we can have that explosion within your engine, the better your gas mileage is. The better your engine runs, more power you have.
This here, if I turn this you can see how all these turns, it works together. Retensioner keeps the tension on your belt, drives your water pump which we, when we do a timing belt, most of the time we recommend you doing that as a maintenance. If you plan on keeping the vehicle, more likely that water pump will go out at some point.
Right here, I have an engine that has met it’s end. And we have got this, probably this is a disassembled. Here your crankshaft, you can see how, when this turns, your pistons are attached to this right here and go up and down, and come back and go up. That’s going on right here inside your engine.
This is your cylinder head, this is your cam gear right here and inside here we have got your valves. And see right here these valves are open, these valves are all closed and nice and smooth and holding all your compression when your piston comes up, and what happens is these things are going up and down. This piston is going up and down towards the valves and you think about your RPM gauge on your car, that sitting at 1000 RPMs or 750 when you are at idle.
At 750 times a minute this piston is going up and down . You think about when you are crossing down the highway or when you are accelerating, this is doing that 5000 times in a minute. Well when that belt brakes, things can go very awry in here.
If you have an interference motor this piston can come up and actually contact these valves , bending the valves, creating a tremendous amount of engine damage in an interference motor, some motors are interference which means that the valves can contact the pistons if they come out of time.
Some are what they call free wheeling which means no damage to be done when the belt is broken but your car will not go anywhere. So what you want to do is check your service manual, replace your belts when it’s recommended, so you are not sitting on the side of the road or do major engine damage to your engine.
Most of the recommendations are somewhere between 90,000 to 105,000 miles depending on manufacture. Some are as low as 60,000 miles depending on how you use your vehicle. In some extreme conditions 60,000 miles is recommended and even though 105,000 mile normal recommendations.
So, check your manual, see when it’s supposed to be done. I’d much rather do maintenance for you than have to do major engine repairs. It’s easier for me and less expensive for you.