I have a 2014 chevy tahoe with 100k miles and have noticed a very low tapping sound when I travel under 5mph, and as I speed up the sound seems to go away. Definitely doesn't sound like it's coming from the engine but from under the vehicle. Not sure what it is? Anybody experience this before? Almost like there is a rock stuck in one of the tires, low volume pop, pop, click, click then goes away as I speed up then comes back as I slow way down.