While driving on the freeway I noticed a whine would appear and disappear before coming back and staying. The whining noise would change with the RPM, like if I put the car in neutral and the RPM dropped. Here's how it sounds at idle. Any ideas on what it is?

 

😱😱 wow. Sounds like a bearing fixing to fall out. Do u have a mechanic stethoscope? If not get a long screw driver or wooden dowel rod an place at certain points on block, head an you will be able to 95% tell where it is coming from once you stick it to your ear an touch other end to place on motor. ( old school ) lol how is the oil in motor?

 

It sounds kind of like the power steering pump running dry. First check the power steering fluid level.

A similar way to pinpoint noise is to use a length of hose. Hold one end to your ear and the other end near the suspected noisy part.

If you can't be sure or it doesn't seem to be one of the external parts, take all the external belts off and start the engine. If the noise is still there, it would be the water pump or the timing belt tensioner. These should be replaced as a set along with a new timing belt.