What are the five words for the must-pass secrets of Subject 4?

What Causes the Smell of Gasoline After Starting the Car?

When there is a strong gasoline smell after starting the car, it is usually caused by incomplete combustion of the fuel. During a cold start, the vehicle's computer adjusts the fuel injection volume based on intake air temperature and coolant temperature signals. At this point, the engine has not yet reached its optimal operating temperature, leading to inefficient combustion, which results in some unburned fuel being expelled. This is why a strong gasoline smell is noticeable during cold starts. However, if the gasoline smell persists even after the car has been running for a while, it may indicate a malfunction. Common issues include: 1. Insufficient air intake through the throttle body: This can cause incorrect air flow readings, affecting fuel injection and increasing fuel consumption, leading to a stronger gasoline smell. 2. Excessive piston carbon buildup: Too much carbon in the combustion chamber or on the pistons can reduce cylinder pressure, causing an overly rich air-fuel mixture and higher fuel consumption. 3. Excessive engine carbon deposits: Heavy carbon buildup inside the engine can impair the atomization of the air-fuel mixture. 4. Fuel line leaks: Leaks at fuel line connections can form sludge, allowing gasoline fumes to enter the cabin through the air conditioning system.

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What is a refrigerated truck used for?

A refrigerated truck is a closed compartment transport vehicle used for transporting frozen foods, dairy products, vegetables, fruits, vaccines, medicines, etc. It is also a specialized refrigerated transport vehicle equipped with a refrigeration unit and a polyurethane insulated compartment. Below is a related introduction: 1. The function of refrigerated trucks: The emergence of refrigerated trucks has enabled many perishable foods such as fruits, meat, and frozen desserts to be transported over long distances under frozen and fresh-keeping conditions. 2. Classification of refrigerated trucks: Refrigerated trucks are divided into two main categories: refrigerated trucks and railway refrigerated cars. Refrigerated trucks are mainly used for food transportation within cities, such as transporting frozen desserts, fresh fruits, fish, and meat from factories to various stores, and sometimes also for medium and short-distance intercity refrigerated transport. Railway refrigerated cars are responsible for medium and long-distance refrigerated food transport tasks. 3. Refrigeration methods of refrigerated trucks: Some refrigerated trucks use ice refrigeration to cool, which means placing a mixture of large blocks of ice and salt in the compartment of the refrigerated truck. This can maintain the internal environment temperature below -8℃. However, this refrigeration method can only last for a limited period. For long-distance refrigerated transport, a series of ice and salt replenishment stations must be set up along the transport route to continuously replenish the ice source and maintain the refrigeration effect.

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How many liters of antifreeze should be added to a car at one time?

A car typically requires about 4 liters of antifreeze per refill. Antifreeze prevents the coolant from freezing and causing damage to the radiator or engine cylinder block/head during cold winter parking. How to choose antifreeze: The basic indicators of antifreeze are its freezing point and boiling point. Market options include -15°C, -25°C, -30°C, and -40°C freezing points. Generally, select an antifreeze with a freezing point at least 10°C lower than your region's minimum temperature. Can different antifreeze brands be mixed? Always use the same brand of antifreeze. Different brands may have varying production formulas, and mixing them could cause chemical reactions between additives, rendering them ineffective. Antifreeze replacement cycle: For vehicles with extended operation periods (e.g., taxis), high-quality antifreeze should be replaced annually. Vehicles with shorter operation periods can be replaced every two years or 30,000 kilometers. To prevent excessive foaming that reduces heat exchange efficiency, ensure the product is within its validity period when adding. Long-life antifreeze can last up to three years. If suspended particles, sediment, discoloration or deterioration appear in the antifreeze, replace it immediately and clean the system.

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How to Adjust Rearview Mirror Position?

When adjusting the rearview mirror, pay attention to positioning the door handle at the intersection of the "midpoint vertically and the one-third line towards the car side." Additionally, adjustment methods vary across different car models, so ensure clear visibility of the vehicle's spacing and trajectory. Below are detailed instructions: 1. Left-side rearview mirror adjustment: For vertical positioning, the ground should occupy the center of the mirror surface. For horizontal positioning, aim to have the car body occupy 1/4 of the mirror while ensuring visibility of the lowest point where the rear wheel contacts the ground. 2. Right-side rearview mirror adjustment: Since the driver's seat is on the left, it's harder to monitor the right side of the vehicle. Therefore, for vertical positioning, the ground should occupy 2/3 of the mirror surface, with visibility of the wheel arch (the curved, protruding part above the wheel resembling an eyebrow). Horizontally, adjust so the car body occupies 1/4 of the mirror. 3. Central rearview mirror adjustment: Adjust the left/right position so the mirror's left edge aligns with your right ear in the reflection. Normally, you shouldn't see yourself in the central mirror. For vertical positioning, place the distant horizon at the mirror's center.

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Does Engine Ticking Noise Require Overhaul?

Engine ticking noises generally do not require major overhauls. Normal phenomena: 1. Cold start noise: Many car owners hear ticking sounds from the engine compartment during cold starts. This ticking noise occurs because the oil pump hasn't fully established oil pressure during cold start, resulting in insufficient lubrication of components. Normally, this ticking noise disappears after the engine runs for a while. 2. Charcoal canister purge valve operation noise: The charcoal canister purge valve opens after engine start, allowing adsorbed gasoline vapors to enter the combustion chamber. This reduces emissions and fuel consumption. This component may produce ticking sounds during operation. Cases requiring part replacement: 1. Engine mount deterioration or loosening: Engine mounts are rubber blocks between the engine and frame that reduce vibration and secure the engine. When these mounts deteriorate or loosen, the engine may shake and produce ticking noises. Replacing the mounts solves this issue. 2. Overly rich fuel mixture: Symptoms include difficult acceleration after start, uneven engine operation, black exhaust smoke, ticking sounds, occasional backfires, reduced power and increased fuel consumption. This is often related to carbon buildup or clogged filters, usually not requiring major repairs. Conclusion: Generally, engine ticking noises rarely lead to major overhauls. Identifying the root cause of the noise can effectively resolve the issue.

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How to Remove the ETC from the Car?

The ETC device on the car cannot be removed because there is an anti-tamper switch button on the back of the ETC device. After installation, this anti-tamper button presses against the windshield. If the device is removed, this button will automatically pop out, and the ETC service will be suspended. You will need to visit the relevant service center to reapply for positioning, installation, and activation before it can be used again. Precautions for Using ETC: The ETC transaction sensing range is 8 meters. When the vehicle in front stops, to prevent the ETC device of the front vehicle from malfunctioning or not having an ETC device at all, you should maintain a distance of more than 10 meters from the front vehicle to avoid automatic sensing and paying for the front vehicle. The recognition speed for ETC lanes is 20km/h. If the speed is too fast, the vehicle device information cannot be read, which will also result in a failed deduction. Unauthorized removal or movement of the OBU device, or if the ETC electronic tag falls off or becomes loose, will cause the electronic tag to become invalid. You can take it to the bank where the ETC card was issued or the highway service office for inspection. If the loosening or detachment is not due to human factors, it only needs to be reactivated.

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What are the five words for the must-pass secrets of Subject 4?

What Causes the Smell of Gasoline After Starting the Car?

What is a refrigerated truck used for?

How many liters of antifreeze should be added to a car at one time?

How to Adjust Rearview Mirror Position?

Does Engine Ticking Noise Require Overhaul?

How to Remove the ETC from the Car?

Does Vehicle Damage Insurance Cover Daily Repairs?

What are the items for the second car maintenance?

Are new cars charged toll fees on highways?

What is required for vehicle inspection in Weihai?