If you’ve ever stopped at a light and noticed your vehicle just feels a little “off”, such as vibrations throughout the chassis, it could be a sign of a more significant issue in your powertrain.
In this article, we’ll cover the common causes of a shaking feeling, what it could mean for your vehicle, and what steps you should take next to get it back to running as it should!
Causes of Shaking at Idle
Worn Motor Mounts
One of the most common sources of a shaking feeling is worn or failed motor mounts. Motor mounts are responsible for dampening the transfer of vibrations between the engine and chassis. However, the soft rubber-like materials that make up the bushings will begin to degrade with time.
Eventually, the mounts can wear down to the point where the material can no longer absorb the forces coming from the engine, transferring those vibrations throughout the chassis. Although the effect of bad motor mounts can be felt during driving, it’s often most noticeable while the vehicle is stopped and idling.
Of course, the best way to prevent this issue is to replace the motor mounts before they reach this point. In general, motor mounts can last between 5-10 years of driving. The exact lifespan of the mounts depends on a variety of factors, including the quality of the mounts themselves, the amount of torque and vibrations produced by the engine, and outdoor temperatures.
Faulty Spark Plugs
Responsible for producing the spark needed for combustion, spark plugs see near constant action in our engines as they fire on every stroke. Over time, these components can experience wear or oil contamination that prevents them from producing adequate spark for ignition.
When this occurs, the cylinder in question will experience a misfire, causing the engine to run rough and inefficient. A motor experiencing a misfire can lead to heavy vibrations as it struggles to run properly.
Misfires are generally accompanied by a check engine light code. If you notice a rough idle and an active CEL, it’s crucial to have your vehicle inspected by a trusted professional as soon as possible to avoid potential further damage.
Idle Air Control Valve Problems
The idle air control (IAC) valve is responsible for controlling the influx of air into the engine at idle, preventing the vehicle from idling too high or low while stopped. Through the use of a servo motor, the IAC valve lets in the adequate amount of air to keep the engine running efficiently.
Problems in the IAC valve, such as debris blockages or servo failure, can prevent the valve from properly managing airflow and lead to either an excess or lack of adequate air intake. These changes in air-fuel ratio can lead to inefficient operation, shaking at idle, and potential stalling.
Failing Alternator
The alternator, which is driven from the engine’s accessory belt, turns your vehicle’s power output into electricity to be used in both the combustion process as well as powering the many electrically-dependent interior components, lights, and safety systems.
Over time, the internal components and wiring of the alternator may begin to wear, reducing the output of electricity. When the alternator is unable to produce the adequate power for the various systems it powers, this may cause the engine to run roughly as the alternator struggles to keep up with demand, sometimes leading to vibrations throughout the vehicle.
Bad Fuel Injectors
Similar to spark plugs, injectors see constant use while you drive. As such a crucial component of your engine, it’s easy to see how faulty or clogged injectors could prevent your vehicle from running properly.
Powertrain Diagnostics in Arvada, Colorado
If you’re noticing an unusual feeling from your engine at idle, or suspect other issues within your powertrain, don’t hesitate to let the diagnostic experts at Arvada Square Auto in Arvada, Colorado today! Our team has extensive experience in pinpointing the source of these issues on a wide variety of vehicles. Give us a call or schedule online today to secure your appointment with the ASE-Certified technicians at Arvada Square Auto!