Shaking when idle and at low speeds can be caused by simple or complex issues. This means that finding a fix to the problem can vary from a do-it-yourself matter to an urgent visit to an auto professional. Either way, the first step in this process is the ability to discern what the underlying cause could be.
When idle, shaking can be caused by the following factors:
Have the engine mounts checked.
When idle, shaking can be mostly like due to faulty engine mounts. Once the engine is turned on, it vibrates. This is a natural thing and the engine is attached to the body by engine mounts. These are meant to mute the vibrations from the engine and prevent transfer of kinetic energy to the chassis. Faulty engine mounts may either perform poorly or not perform at all. This will influence the severity of the shaking but it will still be present.
Engine mount status is hard to diagnose for a novice and as such, this issue will definitely require a visit to the mechanic. This should be done sooner rather than later because shaking increases wear and tear and may damage the engine block itself in the long-run. It can also severely impact car performance.
Check the tires and rims.
The tires are usually the main cause of shaking at any speed. When the car is shaking only when idling, there is a very high chance that the tires are not the culprit.
At low speeds, tires can definitely cause shaking. Tire issues come in three types; worn out tires, poorly aligned tires, and imbalanced tires. Worn tires can be examined at home for faults and defects but wheel alignment and balancing can only be checked and repaired at an auto shop.
Closely related to tires are the rims. They must be in tip-top condition without dents. They must also be compatible with tire size. An imperfect rim or a tire mismatch can cause shaking at all speeds.
Diagnose the transmission train.
All parts of the transmission train work from the moment a car starts. When idle, this may cause minor shaking due to poor calibration. Once the car starts moving, the transmission train keeps functioning with increasing energy as speed increases. It only stops when the car comes to a halt. The cessation of the shaking at high speeds could disqualify the transmission train from being the culprit but not entirely. At higher speeds, a small fault in the transmission train can be overcome by exertion. The disadvantage of this is that a proper diagnosis is a lengthy process that can be both laborious and expensive. As such, it should only be done by a professional. Furthermore, it should not be entrusted to anyone without a proven track record. Another disadvantage is that if you let the problem remain unsolved, it will lead to associated issues that may cost you more over the long run.
A bent axle may also cause shaking when the car is idle and at low speeds. This is a core component that may cause permanent damage to the car. It may also be a very expensive endeavor to fix!
Check the suspension.
When idle, the suspension can cause some shaking but it will be more pronounced when the car is in motion. Since suspension performance is standard at any speed, the shaking due to faulty suspension brushes and mounts will be constantly present. Although pinpointing these parts for sure as the culprit may require a professional service, this whole issue can be easily avoided by sticking to a rigorous service schedule.
Check the brake rotors and calipers.
When idle, faulty brake rotors and calipers are unlikely to be the cause of shaking since the braking system comes into play when the car is in motion. At low speeds, however, they can be identified as the culprit. One easy way to do this is to use the brakes and check if the intensity of the shake increases. Although an increase in intensity may indicate a faulty lower arm link, you will have narrowed down the suspects. Once again, vigilant and regular services are the key to preventing this problem.
Check the propeller shaft.
This cause of car shaking applies mostly to rear wheel drive vehicles. A faulty propeller shaft will interfere with the transmission of power from the back tires. This means that when idle and at low speeds, the car will shake. The shaking may be more prevalent at lower speeds before the streamlining effect of high speeds mutes it.
A car shaking when idle and at low speeds can sometimes be due to the engine horsepower. Some cars are specifically made to behave this way and it could be normal. Old age is another major contributor but this is dependent on the quality of care the car receives.
These problems can be easily prevented by proper maintenance of a strict service schedule. This includes minor services like oil changes and full services like when alignment. You should ensure that the parts used for service are of the highest quality. They should be durable, made to the highest standards and offer good value for money. When a shaking problem arises, the technician chosen to look into the issue should be highly qualified. A poor repair job may do more harm than good. The mechanic may cause a problem that was not originally there; they may have to repeat service or may charge you exorbitant prices.
In the technological age, there are online diagnostic checks that you can do. These usually come in a form that you fill and send back to the website host. They can be used as a guide but any good diagnostic should be done in person. Technicians with years of experience can be able to tell what is causing your car to shake when idle and at low speeds from a simple short drive!