How to Determine a Vehicle's Emission Standard (National Standard)

Why Does the Car's RPM Increase?

An increase in vehicle RPM may be caused by faults in the engine's intake system or fuel system. Below are specific details about engine RPM: 1. During a cold start, if the engine idle speed is below 800/min or above 1200/min, it indicates poor engine condition. 2. While driving, try to avoid letting the engine operate below 2000r/min. If the RPM is too low, the engine will lack power, and operating under heavy load at low RPM can cause damage to the engine and easily lead to carbon buildup. 3. When the engine operates above 4000r/min, the combustion time shortens, leading to incomplete fuel combustion and a significant increase in fuel consumption. If driving in fifth gear at this RPM, the speed usually reaches 150km/h, which is already a dangerously high speed. 4. The most economical and optimal engine operation occurs between 2200~3500r/min. It is advisable to keep the RPM within this range during regular driving.

13

4

Share

Do You Need to Press the Accelerator When Reversing an Automatic Car?

When reversing an automatic car, you need to press the accelerator, but the output torque is very small, and the car will stop if there is resistance. Therefore, you still need to press the accelerator to reverse. Below are the specific steps: 1. Press the car's brake pedal. 2. Press the car's one-touch start button. 3. The dashboard lights up, and the vehicle's power is turned on. 4. Shift the automatic gear lever to the R (Reverse) position. 5. After confirming the safety behind the vehicle, press the accelerator pedal to reverse. Regarding reversing an automatic car, here are some additional steps: 1. When an automatic transmission car needs to reverse, the gear selector should be moved to the R position after the car has come to a complete stop. Otherwise, it may damage the shift actuator or parking lock mechanism in the automatic transmission. 2. If reversing on flat ground, release the brake pedal, use the handbrake, and reverse slowly at engine idle speed without pressing the accelerator pedal. Unlike manual cars, there is no need to worry about the clutch. The brake pedal functions similarly to the clutch—pressing it automatically engages, and releasing it automatically disengages, preventing stalling. 3. If reversing over a step or obstacle, gently press the accelerator pedal and brake promptly after clearing the obstacle. Remember not to press too hard—just a light touch is sufficient.

15

5

Share

Installation Location of Car Navigation GPS Antenna?

Car navigation GPS antenna is installed under the upper cover panel of the center console. Below are detailed explanations about car navigation GPS: 1. GPS consists of three independent parts. Space segment: 21 operational satellites, 3 backup satellites. Ground support system: 1 master control station, 3 injection stations, 5 monitoring stations. User equipment segment: Receives signals transmitted by GPS satellites to obtain necessary navigation and positioning information, which is then processed to complete navigation and positioning tasks. 2. GPS receiver hardware is generally composed of a host, antenna, and power supply.

3

4

Share

Can Brake Fluids Be Mixed?

Brake fluids should not be mixed. Different types and brands of brake fluids contain varying components, and mixing them can lead to a decline in performance indicators and chemical reactions, which may reduce the vehicle's braking effectiveness and impact the fluid's temperature resistance, thereby affecting driving safety. Brake fluid is a functional liquid used to stop wheel rotation, serving to transmit energy, and it also has anti-corrosion, anti-rust, and lubrication properties. Types of brake fluids: Castor oil-alcohol type, made from refined castor oil and low-carbon alcohol; Synthetic type, composed of ethers, alcohols, esters blended with lubricating, anti-oxidation, anti-rust, and anti-rubber swelling additives; Mineral oil type, produced from refined light diesel fractions with thickeners added. Precautions for using automotive brake fluid: If gasoline, diesel, or engine oil is accidentally mixed into a synthetic brake fluid-based braking system, the incompatibility between the fluids can also reduce braking effectiveness. For vehicles that have traveled 40,000 kilometers normally or have used brake fluid continuously for over 2 years, the brake fluid can easily deteriorate due to prolonged use, so timely replacement is essential. For vehicles equipped with a brake fluid level warning device, always monitor whether the warning indicator light is flashing and if the warning sensor is functioning properly. When the brake fluid is insufficient, it should be replenished promptly. The stored brake fluid should be maintained between the calibrated minimum and maximum capacity marks. During normal driving, if the braking feels inconsistent (sometimes light, sometimes heavy), the brake fluid should be replaced immediately. Before replacement, clean the braking system thoroughly with alcohol. If the vehicle's braking is biased, conduct a comprehensive inspection of the braking system. If the wheel cylinder rubber cups are found to be excessively swollen, it may indicate potential quality issues with the brake fluid. In such cases, opt for higher-quality brake fluid for replacement and replace the rubber cups simultaneously. During seasonal changes, especially in winter, if braking effectiveness decreases, it might be due to the brake fluid's grade not being suitable for winter conditions. When replacing the brake fluid, choose one with lower viscosity at low temperatures. Do not mix different types and brands of brake fluids. For braking systems with special requirements, use specific brands of brake fluid. Since formulations vary between brands and types, mixing brake fluids can degrade their performance indicators. Even those brands that claim to be compatible or interchangeable may not perform satisfactorily, so avoid long-term use of mixed fluids. If water is mixed into or absorbed by the brake fluid, or if impurities or sediments are found, replace or carefully filter the fluid promptly. Otherwise, it may lead to insufficient braking pressure, affecting braking performance. Regularly replace brake fluid: The volume of brake fluid changes with temperature variations. Therefore, the brake fluid reservoir is equipped with a vent hole. Air drawn in through this hole may contain moisture or impurities, which can be absorbed or dissolved by the brake fluid, lowering its boiling point. During prolonged driving and braking, the braking system's temperature rises, making the brake lines prone to vapor lock as air is compressed, potentially reducing braking force or causing failure. For driving safety, brake fluid must be replaced regularly.

14

3

Share

What Causes Unstable Engine Idling?

Here are the reasons for unstable engine idling: 1. Excessive carbon buildup in the throttle body and mass air flow sensor. The throttle body and mass air flow sensor are prone to dirt accumulation. Most modern vehicles use electronic throttle bodies, where even minor carbon deposits can affect performance. Excessive carbon buildup in the throttle body may cause throttle hesitation, severe power loss, and unstable idling. 2. Excessive carbon deposits in the cylinder combustion chamber and on pistons. Too much carbon buildup in the combustion chamber can absorb some fuel, slightly prolonging the ignition startup time. Additionally, heavy carbon deposits often form on valves and piston rings, indirectly causing insufficient cylinder compression. 3. Weak spark caused by faulty spark plugs. Spark plugs can also accumulate carbon deposits, which can be cleaned to restore their activity. However, some spark plugs may be nearing the end of their service life, leading to performance degradation. 4. Fuel pressure malfunction. Low fuel pressure results in poor fuel atomization from the injectors, with fuel spraying in lines or even droplets in severe cases, reducing fuel injection quantity and making the air-fuel mixture too lean. 5. Various component failures. Issues such as intake manifold leaks, valve leaks, fuel pressure malfunctions (especially low pressure), and ignition system failures can also cause unstable engine idling.

7

5

Share

Reasons Why the Car Compressor Does Not Rotate

Reasons why the car compressor does not rotate are as follows: 1. Severe internal wear of the compressor, leading to inability to function normally. The compressor plays a crucial role in the air conditioning system, primarily compressing and delivering cold air, which causes the compressor to operate in a high-speed rotating state for extended periods. 2. Check if there is any leakage in the refrigerant, as the compressor will not work without cold air to compress or deliver. 3. Faults in the electrical system are also a very common reason why the car air conditioning compressor fails to operate normally. You can check if the circuit is unobstructed and inspect the temperature sensor solenoid valve.

12

4

Share

How to Determine a Vehicle's Emission Standard (National Standard)

Why Does the Car's RPM Increase?

Do You Need to Press the Accelerator When Reversing an Automatic Car?

Installation Location of Car Navigation GPS Antenna?

Can Brake Fluids Be Mixed?

What Causes Unstable Engine Idling?

Reasons Why the Car Compressor Does Not Rotate

Do 4S shops charge labor fees for maintenance?

What are the procedures for importing cars?

How to Restore a Removed ETC Tag?

What is the appropriate engine speed?