I have a 2017 Impala. 2 months ago I bought new tires, and immediately on the drive home there was really bad oscillation. It’s always hard to describe these things, but it’s something like if you were sitting in the car and someone was pushing up and down on the hood, or when you are driving on a really windy gusty day and it can be hard to stay in your lane, or maybe if lug nuts were loose and a tire was shaking. The tricky part is it doesn’t always happen. It can be completely smooth for many miles, and then shake continually for many miles after that. I only notice it at higher speeds, over 50 mph.
I went back to the tire shop, and they checked the balancing of all 4 tires and said they were fine. They didn’t actually drive it though. They said sometimes jacking the car up causes suspension issues, and trying to diagnose that wasn’t really their thing.
As time has gone on, I’ve noticed it is entirely affected by pavement type. I can be driving along the freeway just fine, and then visually and by change of sound tell that the pavement changed, and then it will start shaking. There is a 30 mile stretch of highway I have traveled several times since I got new tires, in both directions, and the issue never happens there. There are other stretches of road where I know it will happen every time.
Has anyone heard of anything like this, or have any suggestions? I have an appointment at my normal mechanic in a couple of weeks, but he would need to drive it for about 20 minutes just to be able to get out on the Freeway and really see the problem. I also thought about having the tires rotated, since that is cheap to do, and might result in different behavior if it is caused by a single bad tire or wheel.