What Are the Steps to Buying a Used Car?

Does a Car Get Affected If Left Unused for a Long Time?

When a vehicle is left unused for an extended period, components such as the battery, engine oil, lubricants, braking system, and electronic parts may experience varying degrees of aging and damage. Here are some relevant details: 1. Before reuse, it is advisable to thoroughly inspect and replace the "five oils and three fluids," including the battery, engine oil, and coolant. Additionally, the tire pressure of all four tires must be checked, and if severe tire aging is detected, all four tires should be replaced promptly. 2. For vehicles parked for long durations, covering them with a car cover can prevent dust accumulation. Moreover, choosing the right parking location is crucial—avoid parking under trees, in direct sunlight, low-lying areas, or underground parking lots with poor drainage. If possible, opt for an above-ground indoor parking facility. Ideally, start the vehicle at least once a week and drive it for more than 10 kilometers each time, as this is the best way to prevent aging.

15

0

Share

How to Check Engine Oil Level Using the Dipstick?

Park the vehicle on level ground and wait until the engine cools down. Remove the oil dipstick, wipe it clean with a soft cloth, reinsert it fully, then remove it again to check. If the oil mark is below the MIN line, it indicates low oil level; if between MIN and MAX, the oil level is appropriate; if above MAX, there's excessive oil. Here are relevant details: 1. Always check when the engine is cold, as cold measurements are more accurate than hot ones. Temperature affects oil viscosity - high oil temperature may yield false readings. 2. The dipstick must be fully inserted; partial insertion won't provide accurate oil level information. Parking on level ground and waiting for cooling is necessary because most engines use splash lubrication. Only after the engine stops and oil fully drains back to the oil pan while maintaining level can the dipstick show precise oil quantity. 3. Engine oil is as vital to a car as blood is to the human body. Beyond lubricating the engine, it performs cleaning, cooling, sealing, and anti-wear functions. Regular oil checks are absolutely beneficial, especially for models prone to oil consumption issues where more frequent monitoring is essential.

3

Share

The Function and Faults of Oxygen Sensor

The function of the oxygen sensor is: 1. To measure whether there is excess oxygen in the exhaust after engine combustion, converting the oxygen content into a voltage signal and transmitting it to the engine computer, enabling the engine to achieve closed-loop control with the excess air factor as the target, thereby improving the fuel combustion quality of the automobile engine. 2. To ensure that the three-way catalytic converter has conversion efficiency for the three pollutants in the exhaust—hydrocarbons, carbon monoxide, and nitrogen oxides—facilitating the conversion and purification of emission pollutants. The faults of the oxygen sensor include: 1. Sensor poisoning and carbon buildup. 2. Ceramic breakage of the oxygen sensor, burnout of the heater resistance wire, and internal wiring disconnection of the oxygen sensor.

19

2

Share

What are the functions of the clutch, brake, and accelerator respectively?

The functions of the clutch, brake, and accelerator are as follows: 1. The clutch ensures smooth starting of the car and enables seamless gear shifting. 2. The brake is used to slow down a moving car until it comes to a complete stop. 3. The accelerator controls the engine's throttle opening by regulating the amount of pedal depression, thereby managing the air intake. The computer then controls the fuel injection to regulate the engine's speed. Introduction to the brake: 1. Braking refers to the action of stopping or reducing the speed of a moving locomotive, vehicle, or other transportation tools or machinery. 2. The general principle of braking involves fixing a wheel or disc on the high-speed shaft of the machine and installing a corresponding brake shoe, band, or disc on the machine base, which generates a braking torque under external force.

8

3

Share

What Causes Low Idle Speed in Vehicles?

Here are the reasons for low idle speed in vehicles: 1. Oil accumulation and carbon deposits in the throttle body, or dirty intake passages: As the vehicle is used over time, the intake passages can become clogged. Carbon deposits or oil in the throttle body can cause unstable idle speed or even low idle speed. It is recommended that owners clean the throttle body and intake passages to avoid abnormal idle conditions. 2. Weak spark due to faulty spark plugs: Over time, spark plugs can also accumulate carbon deposits. When the deposits become severe, weak sparks from individual spark plugs can affect vehicle performance, leading to low idle speed. Timely cleaning or replacement of spark plugs is advised. 3. Fuel system blockages, such as clogged fuel injectors, or faulty intake pipes: When the fuel injectors are clogged, the vehicle may experience poor fuel pressure and inadequate fuel atomization, resulting in unstable or low idle speed. 4. Malfunctioning sensors: If the vehicle's sensors fail, the correct air-fuel ratio cannot be maintained. Common issues include faulty coolant temperature sensors, oxygen sensors, or throttle position sensors, leading to high fuel consumption and low idle speed.

17

3

Share

Can You Still Drive When the ABS Light Is On?

ABS fault light is on, it is recommended not to continue driving, because the ABS light on means that the vehicle's anti-lock braking system is faulty. During emergency braking, if the wheels lock up, the vehicle will lose control and skid, making it impossible for the driver to slow down or adjust the vehicle's trajectory, posing significant safety hazards. There are various states of the ABS light being on, with different causes and solutions for each state, as detailed below: State 1: ABS fault light stays on (most common). Cause 1: The ABS speed sensor sensing part is covered by mud, sludge, or other contaminants, affecting the sensor's ability to detect the corresponding speed signal. This prevents the ABS computer from determining the vehicle speed and the wheel slip rate, thus failing to issue appropriate commands to regulate braking. Solution: Clean the dirt on the speed sensor and adjust the gap between the speed sensor and the signal ring to restore normal function. Cause 2: Poor signal due to loose connections between system lines or poor contact of the ABS relay, leading to system failure. Solution: Check the line connections and reconnect any loose parts. State 2: ABS warning light intermittently lights up and turns off when accelerating. Cause: When multiple vehicle electrical devices are used, the battery voltage drops below 10.5V. As the engine speed increases and the voltage rises, the ABS indicator light turns off. The ABS system power supply voltage is too low, possibly due to poor terminal contact or grounding issues. Solution: Check the battery specific gravity; inspect the charging system; examine the power supply (e.g., voltage relay or poor power contact). State 3: ABS warning light stays on after engine start and only turns off when the engine is turned off (IGFF). Cause: Poor grounding contact of the ABS hydraulic valve body; poor contact of the ABS hydraulic valve body wire connector; ABS computer failure. Solution: Loosen the grounding screw of the hydraulic valve body, then retighten it, cleaning the contact surface if necessary; check if the connector gap has widened; replace the ABS or ABS/ASR computer. State 4: ABS warning light comes on during high-speed driving. Cause: During high-speed driving, the ABS computer detects a significant difference between the rear and front wheel speed signals; incorrect tire or wheel rim specifications. Solution: Refer to the vehicle's tire and wheel rim specifications, as indicated on the sticker near the fuel tank cap. State 5: ABS warning light intermittently lights up. Cause: Improper adjustment of the brake light switch; poor internal contact of the brake light. Solution: Start the engine, press the brake pedal, push the brake switch linkage down to the bottom with your finger, then release the brake pedal to complete the self-setting position; replace the brake light switch.

8

1

Share

What Are the Steps to Buying a Used Car?

Does a Car Get Affected If Left Unused for a Long Time?

How to Check Engine Oil Level Using the Dipstick?

The Function and Faults of Oxygen Sensor

What are the functions of the clutch, brake, and accelerator respectively?

What Causes Low Idle Speed in Vehicles?

Can You Still Drive When the ABS Light Is On?

What to Do If the ETC Falls Off?

What vehicles can an A1 driver's license drive?

How Often Should a Car Be Serviced for Optimal Maintenance?

Which district in Tianjin does the license plate starting with Jin F belong to?