My vehicle has a little over 4k miles. I was investigating some noise that seemed to be tire noise with a low whomp,whomp,whomp sound coming from the rear while coasting/slowing from 40to30 mph. I had not noticed this before about 3900 miles (but it could have been there before). So I thought I'd check to see if I had thrown a weight. I found that there are no weights on the rear driver side wheel. These are stock tires and wheels and haven't been rotated by myself or touched by any dealer either. All other wheels have around 7-10 5gram weights. Is it even realistic to have 3 tires requiring that much weight and one requiring none? Made me wonder if somehow this one just didn't get balanced at the factory. Thanks in advance for any input?