Generally, we get worried whenever our cars act up in a way they shouldn’t, and we try to find answers or fixes to it. Sometimes, certain actions performed by our car can be completely normal or can be as a result of our own doing or negligence.
For example, a car smoking unusually from its exhaust might leave us extremely worried, only to find out after visiting the car mechanic that it was just a cold start.
In the same way, we might notice that while driving over certain miles per hour (mph), our car begins to vibrate, scaring us because we think it is not supposed to be, and we question why. Why is my car shakes when driving over 70 mph?
Can a Car Shake When Driving Over 70 mph?
Yes, it can. Oftentimes, once a driver exceeds 70 mph and keeps driving at a higher speed, the car tends to shake and start going a little out of balance because of the speed.
Why Does My Car Shake When Driving Over 70 MPH?
The major reasons why your car shakes when driving over 70 mph are:
1. Crooked Car Wheels
This is one of the major reasons why your car might shake when driving over 70 mph.
Once your car wheels are not affixed properly, the nuts and bolts and necessary screws are not tightened properly, and the wheels and tires are not aligned to themselves as they should.
This can also make your car shake at over 70 mph, and asides from shaking, it can lead to raucous steering, quick wear and tear of the car tires, and if it goes unchecked, it might aggravate and lead to an accident.
2. Imbalanced Tires
Tires that are out of balance will make your car shake when you are driving. The whole frame and engine of the car are resting on the tires, so it is important that your tires are firm and properly affixed to their wheels.
If the tire is not balanced, the car resting on it will not be balanced as well, which will make it shake while driving, even at mph less than 70.
Also, if there is a nail on your tire, while you drive at that speed, it may cause your car to shake.
3. Defective Brakes
Brakes are used to bring a car to a halt, either slowly, or all of a sudden to avoid an accident. When brake pads are not firm, or they are faulty, they will affect the steering wheel.
Whenever you try using the breaks, it gets sticky, hard to push, and then results in a vibrating or shaking car while you are driving over 70 mph or even lower.
Once you notice you have defective brakes, you should fix them as soon as possible so as not to endanger yourself and other road users.
4. Reckless Driving
Reckless driving is mostly a result of the impatience of drivers, and another factor that leads to reckless driving is inexperience.
When you drive your car recklessly, you tend to drive higher than the mph required of the road you are driving in at a particular time, and that impatience will lead to your car shaking and vibrating.
When you drive faster than you ought to at a particular time, navigating the road impatiently, even before you see the road ahead of you, chances are that you would stumble needlessly on potholes that you could have avoided, and then this causes damages and misalignment to your wheels, causing your car to shake.
5. Using Unapproved and Unsuitable Gasoline
Car manufacturers sometimes specify the type of gasoline with a certain degree of octane that is suitable for the type of car they have produced, but drivers/car owners don’t take note of this.
Due to their negligence, they use a different type of fuel or gasoline with a lower octane rate from the one recommended, and it leads to inefficiency in the operations of the car, and accumulation of carbon emissions in the exhaust, which will invariably harm your vehicle if it goes without check.
The early signs that your car is using an incorrect gasoline octane is if your car shakes while driving at over 70mph or even lower.
6. Loose Vacuum Hose
Loose vacuum hoses in cars get ruptured at the end of the day, and when hoses rupture, the fuel and air that was supposed to be released proportionately start to puff out indiscriminately, causing sparks in the engine of the car.
Since the air is released wrongly, there will be confusion and loss of power in your car engine, which eventually causes the car to act up, run on roads abnormally when you are driving, and essentially start shaking or vibrating. You should replace loose/broken vacuum hoses once discovered.
7. Unoiled and Un-Serviced Engine
Machines are like human beings. If they don’t eat the appropriate food such as clean fuels, proper engine oils, and good servicing, they tend to get sick and act up.
To ensure the smooth running and driving of your car, you need to provide it with the proper essentials to be healthy. If not, it resorts to shaking and vibrating when you are driving.
8. Low Pressure of Your Tire
You have to set the pressure of your tire to suit the weather conditions so as not to cause quaking of the car while driving over 70 mph.
Ensure that the necessary tools to fix your tire pressure, such as pressure gauge and tire inflator are always in the trunk of the car.
When there is a nail in your tire, it can cause low pressure, endeavor to figure out why you have low pressure, and if it’s because of a nail, know how long you can drive the car with the nail on the tire before having it fixed.
9. Wear of Parts with Time
The older your car gets, the lesser the efficiency of several parts of the car, and when these parts of the car are not working as they should, driving over 70 mph can cause them to give out and cause your car to start shaking.
Ensure that you service your car often, and change the parts that have worn out to avoid this.
10. Damaged Wheels
With time, wheels also become worn out. This term is called ‘Wheel Runout’. It is a situation used to describe when the wheels of your car are not perfectly round, due to nonstop usage.
When your wheels are damaged and are not replaced or corrected, it can also make your car vibrate along the road.
11. Bad Tire Condition
If your tire is in a bad condition, such as a broken or uneven belt not fastened properly, and not detected on time, it can surely lead to the tire bouncing and shaking, as the tires are not in proper conditions.
You should always check the condition of your tires before going on a long trip.
Also, broken bottles on the road can hide in between the streamlines of your tire, causing holes and tears that end up harming the tire. All of these contribute to making your car vibrate on the run.
12. Uneven Car Exhaust System
A bad and uneven car exhaust pipe will also cause your car to vibrate once it is running on over 70 mph.
It could be that you changed the exhaust system, and the one you changed to doesn’t suit the car, or maybe there has been tampering with the exhaust you are using, perhaps a shift, a breakage, or bending. All of these constitute car shakes.
13. Overused Powertrain
When the powertrain of a car is overused or overworked, you hear an unusual noise whenever you are negotiating turns, and it will also affect the brakes of your car, which in turn causes it to shake once you start driving over 70 mph.
14. Damaged CV Joints
The issue with CV joints is that it takes a while before you discover that they are damaged. When the inner CV joints of a car are damaged, it will be difficult to accelerate the vehicle, especially when it is carrying too much load.
Completely damaged CV joints might completely ground your car, but a manageable one might have your car shaking and vibrating when you are trying to accelerate.
15. Unnecessary and Excessive Lifts
Lifting your vehicle excessively can cause incessant vibrations as well. If you keep raising or lifting the vehicle unnecessarily, it will also contribute to it shaking when you are driving above 70 mph. Vibrations while driving can even begin from 50 mph if you keep raising the car excessively.
16. Bad Spark Plugs
This can also affect the car and cause it to vibrate continuously. You must ensure dirty, irregular spark plugs are not used in your vehicle as it affects the engine and causes it to behave erratically.
17. Sludge in Vehicle Engine
This is caused by the bad engine oil, after gathering in the engine, forming sludge that cannot be removed and then affect the car engine, causing it to fail in its workings.
The mild effect will be your car shaking when you are driving, and then if it goes unchecked, it can cause a huge amount of repairs for you.
18. Type of Vehicle
The type of vehicle you are using might also be the reason why your car shakes once you are driving at over 70 mph. If this is the reason, then it is not a fault of yours, but the manufacturer of your car.
Some cars are not strong enough to withstand the speed, some other cars might be too light to sit firmly on the tires, and other factors that are the cause of the manufacturer.
19. Poor Maintenance
Incorrect maintenance of your car can also be the cause of it shaking and vibrating at 70 mph.
When your car mechanic dubiously exchanges parts of your car with something else, or doesn’t couple it properly after servicing, or loses screws and bolts, making parts of your car not tightened properly, it can cause your car to start falling apart, and the first indication is that your car will begin to shake once you are driving over 50 mph.
These are the reason why your car shakes when driving over 70 mph.
Once you discover that your car shakes when driving at or over a normal speed like 70mph, it is advisable to visit a manufacturer-recommended mechanic to inspect what is wrong with the car.
Anyone or more of the nineteen reasons explained above might be the cause. After diagnosis, ensure that whatever the cause is, is repaired before you put your car back on the road.