Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Car sways/rocks violently side to side

It is like floating peacefully along in a canoe on a calm lake, and then being passed by a speed boat. Our 05 Hyundai Sonata sways/rocks violently left to right at speeds higher than 50 mph, when going over bumps, or around curves to the right. It also happens when being passed by tractor trailers on the highway, and when high wind gusts hit the car. It is worse when the car is full of our family and luggage. We just drove from New Hampshire to Georgia and back dealing with this frightening problem the whole way. The Hyundai dealership in Buford Georgia said it was our struts, so we spent $500 on new rear struts. Unfortunately we discovered that was not the problem once we hit the highway to head home. The problem persisted. Our local mechanic in New Hampshire does not see anything wrong, but said it is missing the splash shield under the engine which may cause uneven wind pressure. I truly feel that something is very wrong, but do not know what. Any ideas???

Did The Mechanic Check For A Bad Tire ? How About A Bad Tie-Rod, Bad Ball Joint Or Loose Wheel Lugs ?

If you drive slowly in a level parking lot can you sense or feel the car sashay ever so slightly from side to side ? A tire with a defective belt will give this feeling and the problem that are you experiencing. The fix is new tires.

Turning the tires slowly while observing the tread can locate the problem. Also, usually a tire in this condition will have unusal wear or a high spot {bulge).


How many miles does the car have?

I’d bet that if you changed the front struts, had the chassis gone-over and any loose joints replaced, and got a good 4-wheel alignment, the problem would disappear…assuming, of course, that your tires are good and of the correct size for the car.

You have not reported on if you are running tire pressures as recommended and how close you are to the weight limit established by the manufacture. My first thought is tires, tires, tires, as they are your link to the ground. When all that can be done in regards to the tires I suggest you explore what the aftermarket has available to mitigate this situation. We get a lot of questions about add-ons to a vehicle and most do not make economic sense, this is a circumstance where I think your situation can be improved by and aftermarket suspension component (that is if the answer does not involve the type of tire or how you are running your tires).

Just hit 100,000 miles. We have tire pressure gauges on each tire, and they say the pressure is correct. I have run my hand along each tire and looked carefully for signs of wear or bumps to no avail. I looked for weight limit specs in the manual and did not find any information on that. However, we were carrying 2 skinny adults and 2 small children along with a big dufflebag of clothes, not much weight really. The body of the car feels like it is going to fly off the tires when the sway occurs. The tires actually feel steady beneath us. A slight jerking countersteer to the left can correct the problem at some moments. I will check the “sashay” at slow speeds this afternoon, and we will get an alignment before our next highway trip and after the frost heaves are gone! I will also check with the mechanic to see if he has checked the other things mentioned above. Thank you all; I’ll post again if I learn anything new!

I I’m having the same issue with my 2005 Scion xB. it’s interesting that you mention the engine shield because I no longer have an engine shield and I wondered if that could be the problem. I guess I’m going to try that first.

You should replace that under-engine shield, but doing so will not improve the car’s violent swaying/rocking.

IMHO, you need to have the car put up on a rack so that a mechanic can check the condition of the anti-sway bar (usually referred to as a “sway bar”). It could have snapped, or–more likely–one of its links has probably either snapped or became detached.

When my friend’s Explorer began exhibiting the same dangerous characteristics, I suggested that we check his sway bar links, and–sure enough–one of them had snapped.

Thank you! That is exactly what I decided to do. I’ll post again if I find anything wrong underneath.