What Causes Car to Vibrate When Driving?
Over the decades, as technology progressed, cars improved in every aspect. They became faster, safer, and more refined. Even from generation to generation, we see some improvements that we drivers are happy to have.
Refinement is an aspect we often mention when discussing individual reviews, but part of that is up to the car. The suspension components work with the sound insulation to give us the most refined experience possible, and no one can say no to that. As good as it sounds, things aren’t always perfect.
A car is a complex piece of machinery designed to work flawlessly and provide the performance manufacturers promise. That isn’t always the case, and there are situations where you may notice excessive vibrations. There are multiple reasons for that, and today, I’ll focus on the wheels and tires as a potential problem.
How to Determine if the Vibrations are Normal
This part of the guide is very difficult to explain because not all vibrations are the same. Also, not all vibrations are from the wheels and tires, which I’ll discuss later. As far as the type of vibrations, they can vary quite a lot.
The amount of vibration depends on which component isn’t working optimally and how bad the damage is. Some vibrations can be faint, and not many people will notice them. Others can be quite noticeable, with the worst ones making the car almost undrivable and unsafe.
Since I’m covering the tires and wheels for this guide, you’ll notice the vibrations coming from two places. The first one is the steering wheel, meaning something in the front is causing some problems. With the rear wheels, the vibrations can be noticed throughout the cabin, and you’ll most likely notice them in the seat.
The most important thing to note here is that there are normal and abnormal vibrations. We don’t have smooth roads, so some vibration is expected. Before you start panicking that something is wrong, you’ll need to distinguish what kind of vibration you’re talking about. If you’ve driven your car for a few years, then you probably have a sense of the vibrations you’re noticing. We get accustomed to this, so most drivers will quickly notice a change.
It’s slightly more problematic when you get a new car, at which point you’ll have to figure things out yourself. You have no experience with the case, so you don’t know if the vibrations are normal or not. As always, you can take it to a shop and ask the technician to take it on a test drive with you so that you can get an opinion.
Vibration from Tires
There are multiple tire-related reasons why you may notice some vibration, so let’s look at each one.
Imbalanced Tires
When it comes to vibration from the tires, the most common reason is balance. Tire manufacturers do a phenomenal job of making almost perfectly round tires, with an emphasis on “almost.” A new set of tires comes pretty well balanced from the factory, but it needs some fine-tuning to eliminate the vibrations as much as possible.
An imbalanced tire isn’t something that only plagues new tires, as the ones you already have can have that issue. As you drive, the normal wear and tear on the tires can sometimes cause them to be out of balance, which is why you may notice increased vibrations.
As the tires wear, they may remain balanced, but another problem can occur. One of the weights on the wheel can fall off, meaning that the tire will be out of balance again. It’s not a very common sight, but I’ve had it happen to me once or twice. A quick trip to a tire shop fixes this issue. To be fair, all of these are easily fixable as long as the tire is returned to a “perfectly” balanced state.
The most important thing to note here is that a slight imbalance in tires from the factory or with everyday use is normal. That said, hitting a curb or a larger pothole may cause some internal damage, resulting in some vibration. Unfortunately, this isn’t something that can be inspected easily. The safest way to verify this is to take the tire to a shop. Smaller imperfections can be rectified, but the larger ones, like internal damage, aren’t fixable.
Incorrect Tire Pressure
The second reason why you may notice excessive vibration is due to incorrect tire pressures. From the factory, the manufacturers specify the correct pressure for your model. It’s determined based on multiple factors, with weight being one of the more crucial ones.
There are two types of inflation problems you can face, and in terms of vibration, an underinflated tire will be the bigger one. Overinflated tires may show some vibrations, but they are usually mild. An underinflated tire means the pressure inside isn’t enough to cope with the weight, so it won’t have the intended shape.
During rotation, the “loose” state of the rubber means it will flex and wobble more than it should. This will result in vibrations, and you’ll often notice that they won’t be the same at different speeds. For the most part, you should expect to notice the most vibration at highway speeds.
Uneven Wear
A while ago, I did a guide about uneven wear in tires and spoke about multiple types you may find on your tires. The one we’re interested in for this guide is cupping wear. It looks like random flat spots across the tread, which will cause vibration as the tire rolls. This is because the surface isn’t as round as it should be, so as the tire rolls, you’ll notice vibration.
It’s similar to the regular flat spots you may have from using the handbrake all too often to show off in front of your friends. The idea behind this is the same – that part of the tire isn’t round, and as it rolls, it will create vibrations.
In both of these situations, the tire is a goner. The tire’s lifespan is already reduced, and it’s only a matter of time before it becomes too dangerous to drive. You’re also risking additional damage to other components.
Vibration from Wheels
Like with the tires, there are multiple reasons why you’ll notice some vibration from the wheels. The good news here is that some of them are fixable.
Bent Wheel
Unlike tires, wheels are straighter, and from the factory, they are as close to perfect as possible. As good as it sounds, there are plenty of everyday scenarios that can result in bent wheels. A good example is hitting a curb or a pothole at higher speeds. Sure, the tire will take most of the impact, but it can bend the wheel out of shape.
Depending on the severity of the hit, the vibration will vary. With smaller bents, the vibration will be faint, while for larger ones, it will be much more noticeable. This also means that there will be a difference in terms of the fixability of this problem.
If the wheel has smaller bends, most tire shops can put them back into shape. I’ve had a few of those in my lifetime, and they aren’t a massive issue. Even the alloy wheels can be fixed, so it’s not a problem. Larger bends can be a problem, and not all of them can be fixed. It’s commonly an issue with alloy wheels, as there are situations where it may result in a crack. Some shops promise to fix cracks, but I’m skeptical about the durability of that fix.
Loose Bolts
There are multiple reasons why a wheel needs to come out of a tire. Regardless if you’ve had a flat tire and needed to install a spare, or you’ve just been to the shop for a new set of tires, the wheels need to come off. The entire weight of the car relies on several bolts or nuts, so they need to be tightened properly.
Car manufacturers specify the torque at which the bolts or nuts should be tightened, and you should try to aim for those numbers. Tire shops usually have this information, and they’ll do that whenever they remove the wheels. This is why you should take your car to reputable tire shops. The cheap ones don’t pay too much attention to that.
Also, the bolts or nuts may loosen as you drive along over time, which happens more on cars that drive all-season or all-weather tires. People replace them every few years, so it’s a long time for the wheel bolts to be torqued to spec.
So, what happens when a bolt isn’t tight properly? In an optimal scenario, they tighten the wheel to the hub, where even a fraction of an inch can cause problems. If one or more bolts aren’t tight properly, the wheel won’t sit flush with the hub, and as it rotates, there will be some wobble.
The solution to this is pretty simple. You can retighten them with tools in your car; just make sure you don’t overtighten them. This should be enough to get you to the nearest tire shop and get them torqued to spec.
Other Components That Can Cause Vibrations
Since we are a tire website, we usually cover topics related to that niche. For this guide, it’s important to mention that this is only one part of the story, as plenty of other components can cause vibrations. They can range from problems with the suspension components, axles, bearings, engine, brakes, and more.
This is why taking your car to a professional as soon as possible is essential. Driving with a vibration can be a problem in the long run. Many people ignore the smaller vibrations, thinking that it’s something benign. Sure, in most cases, that’s true, but if left untreated, it can cause some severe problems.
Driving too long with vibration puts additional strain on other components, which tend to break over time. As a result, you’ll notice that the vibration intensity will increase, and at a certain point, you will have a car that’s unsafe to drive.
Conclusion
As refined and comfortable as tires are, there are still some things you’ll notice and see. A perfectly healthy car will have some vibration, but that’s normal because the roads aren’t smooth, the engine vibrates, etc. With that said, there are some vibrations that you shouldn’t ignore.
There are many cases where the vibration you notice comes from the wheels or the tires. This duo takes a lot of beating in daily driving scenarios, so it’s natural to get out of shape. In many situations, the problem is fixable and isn’t very expensive. With that said, there are some situations where the damage is too extensive, and you’ll need to consider replacing a tire or a wheel.
The most important thing to note here is not to ignore the vibrations. As soon as you notice them, take your car to a shop and have it checked out. It may turn out to be something minor, like missing weight from the wheels. Driving too long with vibrations can lead to some catastrophic problems down the line.