In general, the car vibrates when accelerating because of mechanical assembly faults, bad engine components, or the car’s poor alignment of the wheels. However, the following are not the only causes why your car shakes when you press the gas pedal.
Common causes why the car shakes when you press the acceleration pedal are also mechanical problems that can be represented by one or more of your vehicle’s components. The vibrations are also caused by failing engine mounts, suspension mount, steering linkage mount, exhaust system mounts, or generator mounts. All these will usually have to be replaced to fix the vibration issue.
A second reason could be that you have rebuilt your car and forgot to tighten all bolts securely enough so that they vibrate when accelerating due to loosening over time and wear and tear from constant use.
Check the wheels and undercarriage
The main indicator that the wheels or drives of these wheels are to blame for your problems is shaking at a certain speed. Often you will feel the vibration in the range of 80-100 kilometers per hour or 50-52 miles per hour, but sometimes the shaking may be present even at a lower speed, so in any case, you need to fully diagnose the running gear.
The most common problems in this case are represented by the following:
- the wheel mounts are unscrewed, which causes vibration on one of the wheels;
- the brake disc is poorly fixed, at a certain speed it begins to vibrate;
- the wheel drive shaft is bent causing the body to vibrate constantly. These vibrations will increases when accelerating;
- CV joints are damaged. This is one of the most common causes that lead to vibrations;
- damaged wheel bearings, which causes shaking at any speed.
Bad or failing CV joints
As I said above, the CV joints are the first to blame when the car has vibrations when speeding up. To check them, it is enough to grasp the shaft with your hand and try to turn it. If the shaft has a play that is more than a couple of millimeters, the CV joint must be replaced.
Interestingly, this issue can be caused by both external and internal CV joints.
You can also easily determine the malfunction of this chassis mechanism by examining the dust covers. If the rubber part is torn, you can safely talk about the malfunction of this mechanism. If water, dust, and dirt get into the CV joint, the assembly will not last for more than a few days.
Bad wheel alignment
Another reason why car shakes is a bad wheel alignment. When your car sits in one position it wears off the tires unevenly, which leads to discrepancies in tire widths. This creates an imbalance between the left and right sides of your car.
When you hit the gas pedal, one side of the car will dip and rise before finally catching up with the other. This is just another reason why you should regularly check your wheel alignment.
These problems manifest themselves in different ways in different car models. The camber adjustment is one of the first processes that should be performed when you notice vibration and shakes.
What you can do here is:
- Check the wheel alignment angle adjustment at the station with the camber-convergence service;
- Replace the rubber that has visual indicators of uneven or excessive wear;
- Replacing or repairing a rim that has dents and irregularities;
- Balancing the wheels.
Bad of failing engine mounts
Another reason why your car has vibrations not only when accelerating are worn-out engine mounts. A simple way to check is by increasing engine revs when you feel the vibrations.
Problems with the car’s transmission
Also, the culprit for the car’s vibrations can be the transmission. If the car starts shaking at 80 kilometers per hour or 50 mph, you can very easily check the manual transmission’s faults by doing the following:
- Accelerate to a speed of about 85 kilometers per hour or 53 mph;
- Press the clutch and watch for a change in vibration;
- Engage third gear and gently release the clutch;
- Try to accelerate from 50-55 kilometers per hour or 31-34 mph in the last gear.
If the nature of the shaking does not change in all these experiments, the gearbox has nothing to do with this problem, but if the vibrations increase when involving the gearbox then you will need to further investigate the problem
Regarding automatic transmission, things are different because vibrations during acceleration are not common in this transmission type. You can gain a speed of about 85-90 kilometers per hour, then switch the selector to modes 3, 2, D, N and observe the operation of the transmission itself and the change in vibrations.
What damage can vibrations cause to a car?
Vibrations can cause some damage to your car especially if they are caused by engine mounts and other bigger components. For example, increased vibration of the exhaust system elements will lead to the destruction of mechanical joints in this system and the premature failure of some components.
- Increased wear and tear on interior components, such as hard plastic will actively rub against other elements and wear out;
- Damage to the gaskets, which do not tolerate vibration loads, can cause a leakage of some technical fluids and depressurization of nodes;
- Loss of antifreeze circulation systems tightness, elements may become loose, and this will cause the coolant to leak;
- Maximum discomfort of driving in the car, which may cause fatigue on long trips and reduced concentration;
The most annoying thing is that a gradual increase in the resonance of vibrations can lead to the fact that at a certain speed it will be impossible to drive the car at all.
On the other hand, some vibrations require an easy fix. For example, you just need to change the rubber suspensions of the muffler to get everything back to normal. So it is very important to contact the specialists for diagnostics in time, to reduce the discomfort of operating the car and significantly reduce the cost of repairs.