Thumping noise/vibration?

You're describing a broken belt in a tire. When it's as bad you described, you should be able to raise the front tires off the ground, run it in gear, and see the hump, or "tumor" on one of the tires as it goes around. Typically just one wheel will rotate. To make the other one rotate so you can watch the tire, apply the brakes to stop the first one, then place a block of wood under it to hold it. That will force the other wheel to turn. Be careful to not accelerate too much or too quickly as that can cause the first wheel to want to spin again and shoot the piece of wood out.

It might be a good idea to review this article:

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

The alternative is to have the steering and suspension systems inspected at a tire and alignment shop. The people there are experts at finding the causes of noises and vibrations, and at reading tire wear patterns.

This drawing shows two types of broken belts to look for. The most common is on the left. You'll see the hump in the tread as the tire goes around. Be careful when running your hands over that area as it is often accompanied by wires from the steel belts sticking out. Those really hurt when you get poked by them.

The broken belt on the right is a lot harder to spot. With this one, the belt comes apart over such a long period of time the tread has a chance to wear flat, or even, with the rest of the tread. You won't see the characteristic hump. In fact, the tire will look just fine, but in that area, the sidewall doesn't offer the support the rest of it has. That lets the wheel and spindle drop a little each time that spot hits the road surface. Very often there is that one magical speed where the vibration seems to go away. To identify that, look at the grooves as shown with my red line, instead of the tire's surface that hits the road surface. As the tire rotates, you'll see that area rise in one spot. It can take a trained eye to determine if that is bad enough to call a broken belt. There's also little bumps in those grooves that are wear indicators. Those are much smaller than the raised area caused by a broken belt.

With either type of broken belt, an easy way to see it is to watch the steering wheel oscillate back and forth at low speeds, as in when driving through a parking lot. If the broken belt is on a rear tire, you'll feel the seat go up and down, but the steering wheel will remain pretty much motionless.

If it's still confusing, switch a pair of wheels and tires on one side from front to rear, then drive the car to see if the feel or steering wheel oscillations have changed. If the symptoms are the same, switch the two wheels and tires on the other side and try again.

Many people, even inexperienced mechanics, will assume a wheel is out of balance, but the clue here is your observation the vibrating starts as low as 20 mph. You won't feel any imbalance at speeds that low. Even the worst balance problems don't show up until 40 to 50 mph.

A bent wheel can cause similar symptoms. Again, if it's on the front, you'll see it in the steering wheel. If it's on the rear, you'll feel the back of the car moving back and forth. A bent wheel will show up when running them with the car raised up, the same as when you're looking for a broken belt. Watch the lip of the wheel where the weights get attached. If you see that area move left and right as the wheel goes around, that is called "lateral runout". There is usually an allowable specification for that, but it can be too hard to see by eye. We use a dial indicator to identify that runout, but by that time it is so slight as to not cause noticeable symptoms for most people. If you can easily see that runout, it's a lot and is the best suspect.

Let me know what you find.

Thank you for adding that video. Broken tire belts rarely cause an unusual noise. The first thing to be aware of is vibrations and this type of cyclical noise have to be caused by something that is rotating. In this case the best suspect is the brake rotor, especially if the vehicle has been sitting for an extended period of time. Look for a large area of rust, most often on the back side, where a chunk of metal has fallen off. If that area is wide enough, you'll feel a pulsing in the brake pedal, once per wheel revolution.

If you find that rust spot, it usually no longer pays to have the rotor machined. New replacements have come down so much in cost, and to save weight, they are made so thin that often you can't even get one machining out of them without going below the minimum thickness. There's a published legal minimum thickness a rotor can be machined to, (called the "machine to" spec), then the rotor can be allowed to wear down a little more, (called the "discard" spec). The people at most auto parts stores can machine rotors for you, and they can measure them to see if they'll still be legal after the work is done.

If brake work is something new to you, check out this article first:

https://www.2carpros.com/articles/how-to-replace-front-brake-pads-and-rotors-fwd

then, if you want to pursue this, I'll find the instructions specific to your vehicle. Some things to watch for include not getting any grease or foreign material on the braking surfaces of the pads and rotors, including fingerprint grease. Clean out any rust or scale that could get caught between the hub and inside mounting surface of the rotor, and on the mounting surface of the wheel. There's a special high-temperature brake grease that should be used on the sliding pins or sliding surfaces for the calipers, on the backing plates of the pads, and lightly on the center hole for the rotor. Do not use any type of grease on the wheel studs if they have an anodized coating, as most import vehicles do. They will look silver, light yellow, or light blue. That is an electrostatic plating that is a lubricant. Grease will deteriorate that coating and can cause a lug nut to bind and tear the threads next time they are removed. Of course, it's the mechanic taking the wheels off who gets blamed, but the damage was caused the last time the nuts were over-tightened or greased.

A word of warning for those who do not have anodized studs. We like to put a very light coating of grease on them, but then it's good practice to run the nuts on by hand, and then tighten them with the torque wrench. If you use an air impact wrench to spin the nuts on, that grease can build up in front of the nut and get flung out onto the tapered friction surface. That friction surface is needed to hold the nuts from working loose. Grease will prevent that. And absolutely no anti-seize compound on lug nut studs. That stuff guarantees a wheel falling off and will get a mechanic fired.

Be sure to use a click-type torque wrench on the lug nuts. The spec for your car is 72 - 87 foot-pounds. That insures they're tightened evenly to reduce the chance of rotor warping, the wheel won't come loose, a 90-pound weakling can get them off to change a flat tire, and the threads won't be damaged.

Even with all these precautions, it is extremely common for a new rotor to warp in three months. People who demand new rotors under warranty will likely have the same problem in another three months. When we make parts out of cast iron, we set them aside to "age" for three months before they get their final machining. Most new rotors today come from China. There's nothing wrong with their quality, but when they make them, they cast 'em, pack 'em, and ship 'em, then they age on your car. A light cut at the parts store where you bought them will true them up to remove the warpage, then they'll be fine after that. The amount of material removed is not significant. It won't reduce their life and won't send them under the legal limit.

Let me know how you want to proceed.