1：Brake Disc Wear:
One of the most common reasons a car might shake when braking is the uneven wear of the brake disc. This often happens when a driver frequently uses the "tap brake" method, which means short and quick brake applications. In simple terms, if the brake disc has alternating raised and lowered sections, the brake pads will grip this uneven surface, causing the car to shake when braking. Hence, drivers should use their brakes reasonably and properly to avoid such issues in the future.
2：Engine Mount Aging:
The engine mount acts as a shock absorber for the engine. It's designed to absorb the minor vibrations produced when the engine is running. If the engine mount has an issue, these vibrations will be transmitted to the steering wheel and cabin, leading to shaking, especially when the engine is idling.
3：Electrical Load During Idle:
The engine may shake more noticeably when electrical systems like the air conditioner are turned on while the engine is idling. This is because turning on these systems increases the load on the engine, causing a drop in idle speed. To compensate for this drop and prevent shaking, the engine automatically increases its RPM slightly.
4：Tire Issues:
The shaking felt when the vehicle is moving can often be more intense than the shaking during idle. This type of shaking is mostly related to the transmission system, with tire issues being the most common culprit. If you suspect the tires are causing the shake, you can run your hand along the tire tread. If the tread feels jagged or like a saw's teeth, this indicates the tire is aging or deformed.
Furthermore, if the steel wires inside the tire break, they can't hold onto the rubber portion of the tire evenly. This can lead to bulges in the tire, causing the vehicle to shake. Such tires pose a risk of bursting at any time.
5：Throttle and Carbon Deposits:
After driving a certain mileage, a dirty throttle can lead to issues like the throttle not closing tightly, or the idle step motor getting stuck. This results in high engine idle speeds. Carbon deposits in the engine can also cause the vehicle to shake. Especially when starting the car, the engine may shake more than usual, or it might even fail to start in one go.
