How to Repair Air Leakage in Brake Vacuum Pump?

What Causes the Chassis Noise When Driving a Corolla on Rough Roads?

Corolla chassis noise reasons when driving on rough roads are as follows: Loose Bolts: The noise caused by loose bolts is easy to understand. Parts that should be firmly fixed but are not will naturally rattle and produce noise. The noise from loose screws in the chassis is not always a squeaking sound; it can also be a subtle metal knocking sound, especially noticeable when driving on bumpy, rough roads. Examples include loose bolts on various suspension arms, links, and shock absorbers. The mounting bolts of the engine guard plate can become loose after prolonged driving on rough roads, causing noise between the engine guard plate and the chassis. Braking System: Noise from the braking system is usually sharp and continuous. Worn brake pads, uneven wear between the brake discs and pads, among other reasons, can cause brake noise. Brake pad issues are one of the main causes of noise, as brake pads wear out over time and are consumable parts that require regular replacement. Brake pads should be considered for replacement when their thickness wears down to less than 3mm, and must be replaced at 2mm as the absolute limit. Generally, front brake pads last about 50,000 kilometers, while rear brake discs and pads last about 120,000 kilometers. Additionally, poor-quality brake pads (too hard) can also cause noise. Besides brake pads and discs, malfunctions in the brake caliper, master cylinder, or wheel cylinder can also produce noise.

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What are the contents of Subject 3 test?

Subject 3 mainly tests the following contents: vehicle preparation, starting, straight-line driving, lane changing, passing intersections, pulling over, passing pedestrian crossings, passing school zones, passing bus stops, meeting vehicles, overtaking, making U-turns, and night driving. The test procedure is as follows: 1. Vehicle preparation: Start from the right front passenger seat, walk around the vehicle counterclockwise for one and a half laps, check if there are vehicles behind, wait in front of the vehicle if there are, kick the four wheels, and check tire pressure. If no obstacles are found, open the door with the left hand, step in, and close the door. 2. Starting: Fasten the seat belt, shift to neutral, adjust the left, middle, and right rearview mirrors, shift to first gear, turn on the left turn signal, observe the rearview mirror, gently lift the clutch to reach semi-engagement, release the brake, gently steer to the left to complete the start. Be careful not to stall or jerk the vehicle during starting. 3. Lane changing: Before changing lanes, correctly turn on the turn signal, observe the traffic behind through the rearview mirrors, and change lanes after confirming safety. Close the turn signal after completing the lane change. Ensure a safe distance and control speed to avoid hindering other vehicles. 4. Straight-line driving: During straight-line driving, do not move the steering wheel or deviate. Once the speed reaches 35 km/h, release the accelerator to let the speed drop to 30 km/h. The total distance is only 120 meters. 5. Passing intersections: When hearing "Please go straight at the intersection ahead," slow down. If the speed exceeds 35 km/h, reduce it below 35 km/h; if below, just apply the brake. Observe left and right while braking. 6. Pulling over: After hearing "Please pull over," first turn on the right turn signal, observe the rearview mirror, then slow down to about 10 km/h, release the brake, and use the remaining inertia to align with the curb. Avoid stopping at intersections, bridges, bus stops, or public facilities. After stopping, engage the handbrake, turn off the turn signal, and shift to neutral. 7. Passing pedestrian crossings, schools, and bus stops: About 4 meters before the crossing, release the accelerator and brake, observe traffic on both sides, confirm safety, and pass at a reasonable speed. 8. Making U-turns: About 60 meters before the U-turn, release the accelerator and brake, turn on the left turn signal, check the side mirrors, fully depress the clutch, and let the vehicle coast to stop 2 meters before the intersection. Shift to first gear for the U-turn, observe traffic on both sides, and pass at a reasonable speed. 9. Meeting vehicles: Slow down and yield when meeting vehicles, lightly apply the brake, and maintain a safe distance. 10. Overtaking: Maintain a safe distance from the vehicle ahead, turn on the left turn signal, accelerate to overtake, then check the right rearview mirror for a suitable opportunity to return to the original lane. The turn signal should stay on for at least 3 seconds.

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Should the Changan Yidong use 92 or 95 octane gasoline?

According to the official vehicle manual recommendation, the Changan Yidong should use 92 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual, you can also find it marked on the fuel tank cap of the Changan Yidong. Typically, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should use 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should use 95 octane gasoline. However, with the application of some new technologies, the gasoline grade cannot be solely determined by the compression ratio. High compression ratio engines can also be tuned to use lower octane gasoline. This is because, besides the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline grade, the higher the octane number and the better the anti-knock performance. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Changan Yidong occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower octane gasoline, using a higher octane grade will not cause damage, but the increase in octane number may alter the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power and thermal efficiency, with the practical feedback being poorer performance. For vehicles recommended to use higher octane gasoline, using a lower octane grade can cause engine knocking. Due to the significantly lower octane number, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires during the compression stroke, resistance will arise during the upward stroke. This resistance makes the engine run very unstably. If the knocking is imperceptible, it only increases noise without obvious damage to the engine. However, noticeable knocking indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.

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What does Vellfire ECO mean?

ECO refers to the car's economical driving mode function. ECO is an English abbreviation formed from the words Ecology (environmental protection), Conservation (energy saving), and Optimization (power). The Eco mode is further divided into active Eco driving mode and non-active Eco driving mode. When the ECO indicator light on the dashboard illuminates, it indicates that the vehicle's economical mode has been activated. ECO mode is categorized into active and non-active types. The difference lies in the fact that the active type has a dedicated button, allowing the driver to choose whether to activate it. When the driver presses the ECO mode switch, the dashboard indicator light immediately turns on, and the vehicle automatically begins adjusting settings such as throttle opening, transmission shift logic, and air conditioning output power. The non-active ECO mode does not have a dedicated button. When the dashboard ECO indicator light turns on, it serves merely as a reminder function. The ECO system automatically evaluates your driving behavior, and if your current driving operation achieves the optimal fuel supply, the dashboard will simultaneously display the ECO indicator light. Most cars employ the active ECO driving mode, meaning they have a dedicated switch button. Therefore, during daily driving, we can activate the ECO mode. However, it is unnecessary to enable ECO mode when the speed exceeds 120 km/h, during idling, in N/P gear, or in manual mode—especially when climbing a hill. In such scenarios, activating ECO mode would not only fail to demonstrate its fuel-saving characteristics but also negatively impact the vehicle's power performance. Additionally, the ECO mode typically becomes ineffective under the following circumstances: When the vehicle speed exceeds 120 km/h, the system prioritizes speed, causing the ECO mode to deactivate automatically. During idling or when in N/P gear or manual mode, the ECO mode may also become ineffective. When high torque output is required, such as when climbing a hill, the engine control unit prioritizes ensuring sufficient power to drive the vehicle, and the ECO mode will not operate.

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Can 75% Alcohol Be Used Inside the Car?

75% alcohol should not be used directly inside the car. It is recommended to first dilute the 75% alcohol and then use a towel dampened with it to wipe necessary contact points such as the steering wheel and gear lever. Do not apply alcohol to genuine leather seats or decorative leather, as leather contains proteins that can react with alcohol, causing discoloration, deterioration, or hardening of the surface. Additionally, avoid using alcohol on painted interior trim pieces, as alcohol can damage the paint and reduce the gloss of the trim. If the concentration of alcohol in the air reaches a certain level, improper handling may lead to combustion or even explosion if exposed to sparks or during vehicle operation.

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How to Know the Tire Model?

The model and specifications of a tire are generally marked on the tire sidewall, and the information usually includes the tire size, aspect ratio, and tread width. The wider the tread width, the larger the contact area with the ground, which improves the driving feel and stability of the car, but the corresponding fuel consumption will be higher. Tires with a lower aspect ratio have thinner sidewalls, which enhances their ability to receive road feedback. Additionally, tires with a lower aspect ratio provide better lateral support and handling. As one of the important components of a car, tires are responsible for supporting the entire vehicle body and transmitting direction, forming good contact with the ground to ensure safe driving on the road.

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How to Repair Air Leakage in Brake Vacuum Pump?

What Causes the Chassis Noise When Driving a Corolla on Rough Roads?

What are the contents of Subject 3 test?

Should the Changan Yidong use 92 or 95 octane gasoline?

What does Vellfire ECO mean?

Can 75% Alcohol Be Used Inside the Car?

How to Know the Tire Model?

What Causes a Mercedes-Benz to Fail to Shut Off?

How to Open the CR-V Hood?

What is the actual fuel consumption of the Beijing BJ30?

What's the reason for the failure of Boyue's automatic window locking?