Timing belt replacements are one of the few times as a car owner you’ll likely feel like you’re truly being ripped off. So, is that the case? Should you be putting it off?
The answer to both is actually a pretty resounding no. Surprisingly this is one of the few times that a high price is probably warranted and you should definitely not put it off.
Why is that though?
Timing belts are a small rubber/kevlar belt with a number of teeth on them that keep the motor in time. Keeping the motor in time is the act of making sure that all of the top of the motor is spinning in unison with the bottom of the motor and is one of the really important aspects of the engine running at all.
In the early days of cars, this was done using sets of gears or chains that would connect the bottom of the motor (the crankshaft) to the top (the valvetrain), as well as driving things like the water pump, oil pump and fuel pump. The great thing about these old motors is that they were very stout, rarely worked hard at all and were not interference motors (this is an important term).
As time went on though, both the need for more power and the need for efficiency both went up drastically. Through the first boom of the muscle car in America and the oil crisis in the 1970’s, when Japanese built cars became super popular. The attraction of these small economical Japanese cars was far better fuel economy and much better power from the size of the motor, all achieved through the adoption of new technologies and different valvetrains like overhead cam.
This new style of valvetrain bought with it a quick death for the gear system, its size, noise, weight and horrific cost. In early motors where the valvetrain was near the bottom of the motor, these gear systems took up little to no room. However, when the valvetrain was moved to the very top of the motor, these gear systems suddenly became very heavy, very noisey and very complicated, often wasting a lot of space.
These horrific inefficiencies were only contributing factors in the failure of the gear system though, the final nail in the coffin was cost. Being that many of these newer, more economical motors were being built in post war Japan, the cost and availability of raw material forced the hand of innovation and allowed the introduction of timing belts.
The next of these issues comes through slowly from the 90’s to the mid 00’s with the introduction of interference motors. Interference motors began to see more common use mostly due to higher compression ratios, which allowed engineers to make more power from a much smaller engine. With the growing knowledge of the role cars play in global warming and the introduction of higher emissions standards, manufacturers were forced to be creative with their motors.
So, how does this relate to changing timing belts?
Well, unfortunately interference motors have one fatal drawback, the interference they're referring to is the fact that the top of the motor can smash into the bottom of the motor if timing is lost.
A failed timing belt in one of these motors is likely to cause internal damage to the motor. Meaning either a new motor or a lot of repair work. Due to the rubberised nature of these belts, aging and the proximity to heat, these belts become brittle and can snap.
The other thing to take into consideration here is that timing belts are often located right near the beating heart of the engine to make sure everything is running right and in time, making them an absolute pain to change.
For these reasons, you’re probably not being ripped off for replacing a timing belt and it is definitely worthwhile. However, always double check the price you’ve received with another mechanic, such as our Kashy mechanics.