How do you know when to replace a car belt? 2001 Toyota Corolla. 151,000 miles+?

My car has begin needing a lot of attention lately. I just put new tires on it about 2 weeks ago. The brakes need replaced which I hope to get to this weekend. I have noticed a sound coming from under the hood. It doesn't sound horrible, just abnormal. The only thing I could think of is the belts. I am not real sure of car technology, and was hoping I could get some help. How do I know whether it's the belts or something else? I don't want to just carry it to a repair place without having some idea what's wrong. My car is a 2001 Toyota Corolla with 151,000 miles + it has been took care of. My dad gave it to me, he owned it previously. He got it from the dealorship when it had 20,000 miles on it. What kind of routine maintaince should I be taking it in for right now? The car is up-to-date on its oil changes; it was just changed 1,000 miles ago. I know little about cars and I am trying to learn as much as I can about their upkeep. Thanks for your help in advanceHow do you know when to replace a car belt? 2001 Toyota Corolla. 151,000 miles+?Which belt? Serpentine belt ( it drives the accessories such as the alternator, power steering, a/c compressor etc. ) or the timing belt ( which is usually covered to protect it from dust )? At your mileage, the timing belt is definitely overdue if it has not been changed ( most manufacturers recommend to change it at ~ 100,000 miles or 160,000 km ). The serpentine belt you can inspect yourself. Flip it around ( to see the grooves ) Is it showing cracks in the grooves or does it look shiny/glazed? If so, it's time to have it replaced. Also, a noise from a belt may not be the belt itself but rather the belt tensioner.How do you know when to replace a car belt? 2001 Toyota Corolla. 151,000 miles+?I am betting its a pulley bearing going bad. Either an idler or tensioner. If your belt has any noticeable cracks or is hardened or glazed, change it. If its the original, t will be wise to change it anyway due to its sheer age. I would never let a belt go past 60,000 miles.How do you know when to replace a car belt? 2001 Toyota Corolla. 151,000 miles+?Probably the water pump making the noise. Replace the timing belt at the same time as you replace the water pump. It is the same labor.How do you know when to replace a car belt? 2001 Toyota Corolla. 151,000 miles+?Any car with 151,000 miles will need attention. I think you need to take it in and describe the noise. They will tell you what's wrong. Take it to another place then and see if you get the same answer.How do you know when to replace a car belt? 2001 Toyota Corolla. 151,000 miles+?from all indications it looks like you have kept this vehicle in good shape. One of the things i would be concerned about is the timing belt. As for the belts see if they are cracked or worn. If they are they should be replaced. This vehicle could very easily last another 100k. good luck