Driving on highway today with my business partner in the passenger seat and after entering the highway we both felt a rhythmic bumpiness through the seat. Very damped though, like you were traveling over small smooth bumps a foot apart. No sensation of it in the steering wheel. Doing about 70 mph in dynamic and sport. Switched out of each and feeling seemed more pronounced. Lasted about 30 minutes. Started again towards the end of 90 mile trip. Same thing in reverse on the way back. Tires are overinflated by 3-5 lbs.- could that be causing it? 7k miles on the oem tires and the car since new. Wheel out of round? Bad roads? This an interstate toll road. I'm taking it to a local mechanic to have wheels and tires looked over as my dealer is 90 minutes away.

The feeling was like a car with bad shocks, but with very small vertical travel over consistently uneven road. Almost Nauseating feeling from the rhythmic bumpiness. Thoughts welcome.

 

I get this sometimes, too, so I'm curious whether it's "normal" or something that can be fixed.

 

Most likely the wheels are out of balance. The vibration usually reveals itself at the speed between 55 and 70 MPH. It usually disappears with the speeds outside of this range. And the fact that the steering wheel is not vibrating points to the rear wheels (or wheel)

 

Sounds very much like when I had a slightly bent front wheel. But I also felt that through the steering as well as the seat. I agree with ololly that your case might be a rear wheel.

 

Although unlikely as the cause of your issue; could it have been the pavement itself.. I have noticed that roads that have heavy truck traffic, just after the frost is out of the road, can sometimes produce a feeling something like you describe. Not potholes, but a regular undulation in the surface.
Lawrence

 

All 3 thoughts already provided are possible:
1. bent rear rim
2. out of balance rear wheel
3. road surface.


Mulmer's thinking on the road surface was also my first thought. This will happen most frequently on concrete surfaces with evenly spaced expansion joints. Try an asphalt paved state highway at speed before you waste money at the wheel/tire shop.


Those bumps you were feeling were probably occurring every 50 feet or so. At 70mph , you're covering over 100 feet/second

 

Road surface was also my fist thought given the description. Here in Los Angeles, certain freeways have a rhythmic bumpiness to them, which changes with wheel base etc.
CRS

 

Thanks for the responses gents. The surface may have been concrete in the areas where this happened. If it was a rear wheel, out of balance or bent, wouldn't it be felt all the time?
Is the dynamic suspension of the f type more sensitive to an uneven road?

 

I don't think it's the road or the wheels in my case, because it doesn't happen consistently or always on the same stretches of road. I think it's in the suspension, which seems to get caught in a pogo effect that gets started and doesn't seem to want to stop.

 

Are you saying the particular wheel base of the f type may make the uneven surface more pronounced?

 

Great description. A pogo effect is a good way to describe this feeling with a very short amplitude! Is your car awd? It's the consistency of the movement/feeling that makes me suspect that it's a response coming from the car.

 

Yes, 2016 R.

 

The original description said something about bumps a foot apart but not considering the speed, that description made me think of a cupped or scalloped rear tire which could be induced by 1 or 2 above or other suspension problem. Besides reconfirming on alternate surfaces, before you take it in, run your hand around the outside of the tire and you might be able to feel little cups in the tread.

 

What would have caused what you describe?

 

I think you should apply some troubleshooting process. Eliminate one variable at a time. Start with the cheapest options. Go to the nearest Discount Tire or Tire Rack shop and ask them to balance your wheels. $40 later they will eliminate (or confirm) problems with tires/rims - bent, bubbled, unbalanced etc... If everything is fine you will still retain this problem, but at least your wheels will be in balance now, which wouldn't hurt in any case.

If you go with this problem to a dealer that's where they'll start as well, but at least they can eliminate wheels issues (at the dealer's rates it could be pricey)

 

As usual, you've echoed my thoughts to a "T".

Dave

 

Well, thanks for your input and comments everyone. The answer is no. 3, the road. As CRS, Unhinged and others surmised the road is causing the problem due to:

Concrete surface- edges of concrete curl upward at control joints with less than perfect curing after placement causing the mogul affect; Combined with f type wheel base at certain speed. Confirmed by variety of design professionals who also drive this stretch. One of my other business partners experiences this in his Toyota Tundra, but another partner in a Toyota Highlander does not. As pointed out speed is also a factor. I also wonder if the jags dynamic suspension makes This effect more prounounced. The curling of the concrete could be minimized with better curing. Really unsettling driving over this surface.

 

Why do you overinflate your tires? Just wondering. I wish this car could display the pressure of each tire as my last car did, I miss that feature.

 

It's in the gauge cluster menu. Go to vehicle information.

 

Older cars don't have the option to display tire pressure. Not sure when they added that, maybe MY16?