Not unless they are damaged or faulty.
There is no timing belt in a 2002 Echo. It has a chain, and there is no service interval for it. If it starts making noises, have it checked out. It could last for hundreds of thousands of miles.
Timing chain. I checked with dealer's service yesterday regarding my daughter's car. No periodic change required.
timing BELT ( checked on 2007 )
Some car companies tell you to replace the timing belt every 60k -100k miles, I would go by that. because there is really no way to check if the timing belt is bad because some simply snap, some may lose their teeth before they snap and this can cause major problems in itself, but you want to have the timing belt replaced before any of this happpens. so go by the recommended service interval for your car. It is an expensive part to replace because it is somewhat time-consuming, and you will want to replace the water pump and the other belts while you are in there.
About $1500.00 for just the belt service at a quality provider.
118d has a timing chain that requires no service or change during its lifetime.
Have you checked if its a belt or a chain?
Have you checked at a parts store on the new belt package?
There is no routine "service" that can be done to it. It can only be replaced and the factory recommendation mileage is every 90,000 miles. Note: Strongly consider replacing the water pump at the same time, since the work in order to get to it is exactly the same.
1/2"
If you checked the belt and you think it is loose ,change it. It has a tensioner built in that sets the tension when the belt is installed.