Q: Engine noise at 3500 RPM

Generally, they are just worn-out fan belts. You might just look at them, or if they are 4-5 years old, have them all changed. They are rubber and only last so long. They stretch, they wear internally, and if they crack, you definitely want to put the new ones in. That’s normal. But if you put new fan belts on and it still screeches, then something is wrong. There is a bearing that starts to wear out that makes them screech and you’ll want to fix that. If you do have new fan belts put on, when the old one is taken off, check all the bearings and alternator, water pumps, and pin them. If they wobble or grind, and make noise, replace those before you put the new fan belt back on. If you want to have this checked before making any repairs, a technician from YourMechanic can diagnose your car’s noise and resolve this issue for you.