Weird shaking after getting new tires

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.

welcome STCH10
I suppose lifting the vehicle could of put stress on a failinf or defective suspension part causing your problem. I am sure your mechanic will check this out.
do you here any noises when this happens? if you do that would be a sign of something has failed.
have you checked your new tires for being over inflated? if they are it might give you different handling feeling. but probably not to the extreme you are saying.

I suspect you need a tire store with a road force machine. It rotates the tire agaimst a roller and measures force variation in the tire. Rotating the tire with respect to the wheel can be a fix. Or if the tire is too far out, replacement.

Your tires also could be statically balanced. but not dynamically balanced. If there are not weights on the inside and outside of at least 2 of the 4 tires, they have not been dynamically balanced.

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Agree, tires aren’t balanced well or one of the tires is too far out of spec to be balanced. Are they cheap tires? No offense. I’ve bought cheapies before.

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To answer a few questions, I do not hear any noise when this occurs. It’s a little harder to check for odd noises since this happens at high speeds, but I don’t notice anything out of the ordinary.

All 4 tires are at 33 psi, as recommended.

These are Bridgestone Turanza tires, so I don’t believe they would be considered to be overly cheap. They allegedly have a 90 day risk free trial period even.

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Regarding the last set of tires I put on my Sonoma about 4 years ago, they were balanced 4 times by 3 different facilities. Twice by the installer store. Always an imbalance.

I have an old manual Micro wheel balancer and while doing this is one of my least favorite jobs on the planet I checked the balance and 3 of the 4 were out by 1/4 to 1/2 ounces.
Balanced them and no issues afterwards.

For what it’s worth computer balancers need to be calibrated ever so often and some balancers (such as the way overpriced Snap-On unit that a dealer I worked for purchased) was garbage from the start.

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This statement is true.

What usually happens is the valving in shocks/struts can get messed up when raising/lowering a vehicle.

And then you can get what’s called tire bounce.

Have the struts checked.

Tester

Is there a possibility of a defective belt in one of the tires?

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This doesn’t sound like a tire balance problem to me. The tires indeed may not be properly balanced, but the symptom seem beyond what imbalanced tires would cause. My guess something has come loose in the suspension or steering system. OP should be extremely careful until this is properly diagnosed. The best bet is to not drive this vehicle – except perhaps at less than 30 mph for 7-11 trips — until then.

The only time I’ve experienced that sort of symptom, it was caused by what the OP mentioned already, loose lug nuts. That was a wild experience I must say. I couldn’t blame anybody b/c I was the only one messing w/the lug nuts prior to the incident.

Regarding tire balancing: I driveway-mounted and balanced 8 new tires a couple years ago, two separate vehicles. The way I do it, I first put the rim on the bubble balance machine, then place the tire on it, rotating it until the tire/rim combo is at its best balance position. Then I mount the tire in that orientation, then use a small wheel weight or two if necessary to complete the balance job. Most tires, no wheel weights at all were needed. Never had any tire vibrations problems from any of those wheels.

No, Bridgestone isn’t a cheap tire. It wouldn’t be out of the question for even a good tire company to let a defective tire slip through quality control, though. Rotating the tires to see if the vibration changes isn’t a terrible idea. If you do, I’d move the front tires to rear to see if the steering feel changes. I’m kind of hesitant to think it’s a suspension issue since the car is a 2017, but anything is possible.

All that said, I suppose I’m not much help. I still think it’s going to be a balance or a tire defect issue myself. I think the tire shop should’ve at least driven it. They would probably know better what a tire defect vs the suspension issue they mentioned would feel like.

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How would you check the struts’ valving? Bounce test at all 4 corners?

+1
At this point, many tire stores have added the Hunter GSP9700 Road Force Balancing Machine, but not every shop has one. Road Force balancing on one of those machines is likely to help–a lot.

However, that being said, it could also be the tires themselves, rather than their balance. I say that because the OEM Continental tires that came from the factory on my 2011 Outback produced very strange vibrations that could be felt in the steering wheel when I drove on a particular 15 mile stretch of I-287. It was the type of vibration that caused my hands to go numb after just a few minutes.

This problem persisted, even after Road Force Balancing. However, when I replaced those Continentals with Michelin Defenders, I never again experienced that problem on that stretch of road. Something about the internal construction of those Continentals was just not a good mix with that stretch of highway.

I’d rotate the tires, and see if the problem “moves” with the tires. Or if there’s any change at all.

You may have gotten a bad tire, or even bad tires. It happens.

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When I worked on SAABs the PDI (pre delivery inspection) procedure was very thorough.

One new SAAB had a subtle vibration at highway speeds and I determined that the right front tire had a manufacturing fault. Replaced it and the car was fine; and that was a new tire on a new car with less than 2 miles on it. Any assembly line product is going to have a certain percentage of failures; from a bottle of beer to an airliner. The bean counters figure this in.

And Tester is correct that a strut or shock can suddenly fail just by raising the car and unloading the suspension.

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Did you pay extra for the massage? :grin:

Luckily no, but at least I got a Happy Ending when I dumped those Continentals and replaced them with Michelins.
:smirk:

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really, where do you get your tires? LOL

Since this only happens on certain road surfaces and it happens every time you drive on those surfaces, this may simply be a case of a tread pattern that doesn’t “like” those surfaces. There may be tread squirm that may or may not go away as the tires wear.

I think you nearly stepped on the third rail with that.

Did everyone except George San Jose miss this quote? This indicates the problem isn’t tires at all but the road. There are indeed roads where this happens!

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