On which days can I schedule the Subject 1 exam?

What Causes the Loud Roaring Noise from Tires Inside the Car?

Tire quietness is a crucial indicator of driving experience. When abnormal roaring sounds occur inside the car, it can significantly degrade the driving experience. The reasons for tire noise are as follows: 1. Low tire aspect ratio: Larger contact area with the ground increases the friction coefficient, resulting in louder tire noise. 2. Recent tire replacement: Poor wheel alignment during the replacement process or issues with the bearings. 3. Insufficient body rigidity: Causes friction or shaking between the car doors and the frame while driving, leading to abnormal noises from the body. 4. Road noise: Rough or uneven road surfaces are also one of the reasons for loud tire noise. 5. Poor sound insulation in the car: Inadequate sound insulation leads to the phenomenon of roaring sounds inside the car.

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What Causes Severe Car Vibration?

If you notice slight vibration or deviation in the car body during driving, it is usually caused by tire-related issues. The specific explanations are as follows: 1. Poor Tire Balance: The primary cause may be poor tire balance. The owner should promptly perform a four-wheel alignment and dynamic balancing. If the vehicle doesn't pull to one side, just doing a tire dynamic balance should suffice. 2. Deformed Wheel Hub: This condition is more serious and may be caused by a deformed steel rim, requiring the owner to visit a professional repair shop for inspection. This situation generally occurs in vehicles that have been in use for a long time. Typically, when replacing new tires or new steel rims, a tire balance should be performed. Otherwise, uneven weight distribution can easily cause steering wheel vibration. Body vibration affects both driving comfort and handling judgment. 3. Deformed Drive Shaft: Another possible cause is imbalance due to a deformed drive shaft. This situation is more common in vehicles that have experienced chassis collisions.

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What does fault code u111300 mean?

Fault code u111300 indicates that the ABS operation signal is out of tolerance. The Anti-lock Braking System, commonly referred to as ABS, is a safety system that prevents the wheels from locking up during braking. Here is some relevant information about ABS: 1. The function of ABS is to automatically control the braking force during vehicle braking, preventing the wheels from locking up and maintaining a state of rolling and sliding (with a slip ratio of around 20%), ensuring maximum traction between the wheels and the road surface. 2. When the wheels are about to reach the next lock-up point, the brake fluid pressure causes the system to repeatedly engage and disengage, operating 60 to 120 times per second. This action is similar to continuously applying and releasing the brakes, akin to mechanical 'pumping' of the brakes.

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What are the symptoms of insufficient refrigerant in a car's air conditioning system?

There are two main symptoms of insufficient refrigerant in a car's air conditioning system, as detailed below: 1. When the air conditioning system is operating normally and continuously, if bubbles persistently appear in the sight glass, it indicates insufficient refrigerant and the need for a recharge. 2. Open the car's hood and check if there are oil stains at the air conditioning system's joints. If present, this typically indicates refrigerant leakage. It's recommended to clean the area before recharging. 3. Most car air conditioning pipe connections use threaded joints, which are prone to vibration during driving. Generally, it's advised to recharge the refrigerant every two years. However, if a recharge is needed again within months, there must be a refrigerant leak that requires inspection to locate the leak point.

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What Causes the Steering Wheel to Become Hard to Turn?

Steering wheel becomes hard to turn due to insufficient power steering fluid, low tire pressure, or malfunction of the steering gear or power steering pump. Insufficient power steering fluid: Power steering fluid is a medium oil used in the car's power steering pump, serving to transmit steering force and provide cushioning. The power steering fluid needs to be replaced regularly, and checked for leaks. When the fluid is insufficient, the steering will feel heavy and stiff. The power steering fluid should be replaced or replenished as soon as possible to ensure normal vehicle operation. Low tire pressure: Low tire pressure increases the contact area between the tire and the road surface, leading to greater friction and making steering more difficult, resulting in a heavy steering wheel, which is not conducive to driving safety. Tire pressure should be checked frequently, and if the pressure is insufficient, it should be replenished promptly to ensure normal vehicle operation. Steering gear or power steering pump malfunction: The steering gear and power steering pump also affect the car's steering. Any malfunction in these two critical components can cause steering difficulties. Issues such as universal joints, chassis suspension stabilizer bars, or plain bearings should not be overlooked. Any problems detected should be repaired promptly.

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Does the Transmission Filter Need to Be Replaced?

Transmission filters need to be replaced for models without a transmission oil drain hole. Below are the specific details about automotive transmission filters: 1. Function of the Filter: During the use of a vehicle, friction between mechanical metal components inside the transmission can generate impurities and metal debris. The transmission oil filter's role is to filter out iron filings, sediment, and other impurities from the transmission oil, supplying clean oil to various components for lubrication and cleaning purposes. 2. Explanation on Whether to Replace the Filter: Some vehicle models do not have a separate transmission oil drain hole, requiring the oil pan to be removed for an oil change, which necessitates replacing the filter at the same time. Models with a separate transmission oil drain hole have maintenance-free filters that do not require replacement. 3. Replacement Interval: The replacement of the transmission filter depends on the transmission oil change schedule. Automatic transmission oil should be replaced every two years or approximately every 40,000-60,000 kilometers, while manual transmission oil should be replaced every three years or every 60,000-80,000 kilometers. The transmission filter is replaced along with the transmission oil.

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On which days can I schedule the Subject 1 exam?

What Causes the Loud Roaring Noise from Tires Inside the Car?

What Causes Severe Car Vibration?

What does fault code u111300 mean?

What are the symptoms of insufficient refrigerant in a car's air conditioning system?

What Causes the Steering Wheel to Become Hard to Turn?

Does the Transmission Filter Need to Be Replaced?

What is the maximum extension period for vehicle inspection?

What are the four situations when the ETC barrier does not lift?

How Many Types of Diesel Fuel Grades Are There?

How Many Liters of Coolant Are Needed for a Classic Sylphy Coolant Replacement?