When I am driving I dont hear but as soon as I climb up in the rpms the sound is apparent as I slowing down in the rpms.
My car has 169000 miles.
My car has a manual transmission.
Among the possible sources of this noise are accessory drives (pulleys, alternator, etc.), the timing belt (or serpentine belt) tensioner, and loose heat shields. The fact that use of the a/c worsens the noise would point toward the serpentine belt circuit of components but that is speculative until the car is actually inspected. If you desire a resolution to this, the recommended service is a vehicle noise diagnostic. If you request that service, the responding certified mechanic will definitely find the origin of the noise and let you know of the recommended repairs. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing