What causes a popping sound when starting the car?

1 Answers
Rose
07/30/25 8:52am
Car makes a popping sound at ignition moment, which is caused by incomplete combustion. This sound occurs when the air-fuel mixture enters the exhaust pipe and burns. It is recommended to clean the throttle body, fuel injectors, and carbon deposits in the intake tract to solve the problem. Additional information: 1. Car carbon deposits: Carbon deposits are accumulations formed when fuel and lubricating oil exhaust cannot be completely burned (main components include hydroxy acids, asphaltenes, tar, etc.). The formation of these deposits is directly related to the car's "fuel" and "lubricating oil". 2. Hazards of carbon deposits: They reduce engine power, cause uneven and gradually decreasing power output, increase fuel consumption, add economic burden, and make cold starts difficult, especially in winter.
Was this review help?
14
2
Share
More Forum Discussions

Will the other party be fully liable for compensating modified headlights?

No, the insurance company will only compensate for the original factory assembly, as modified parts are not covered under the claim. Precautions for modifying car headlights are as follows: 1. First, check the lighting configuration: It's essential to understand the lighting configuration clearly. Even for the same car model, the headlights may differ depending on the trim level. Generally, lower trims come with halogen lights, while higher trims may feature xenon or LED headlights. 2. Check if the original car has a lens: Taking the original halogen lights as an example, if they come without a lens and only have a reflector bowl, modifications will require drilling holes in the original reflector bowl for installation. For halogen lights with a lens, since the new xenon headlights and the old lens may not match, scattering of light can occur. To avoid this, it is recommended to replace the old lens with a new xenon bi-xenon lens and use a dedicated bracket for installation.
17
2
Share

Why does the Volkswagen Jetta make noise when the air conditioning is turned on?

The following are the specific reasons for the noise when the Volkswagen Jetta's air conditioning is turned on: 1. Compressor electromagnetic clutch failure: Since the compressor often operates under high load and changes speed from low to high, the requirements for the electromagnetic clutch are very high. The installation position of the electromagnetic clutch is mostly close to the ground and often comes into contact with rainwater and mud. When the bearing inside the electromagnetic clutch is damaged, it will cause noise. 2. Improper tightness of the compressor drive belt: If the compressor drive belt is too tight or too loose, it will affect the lifespan of the electromagnetic clutch. If the drive belt is too loose, the electromagnetic clutch is prone to slipping. If the drive belt is too tight, the load on the electromagnetic clutch will increase. 3. Lack of lubricating oil in the compressor: Improper use of lubricating oil may cause the compressor to wear out and become unusable.
18
5
Share

What are the causes of BMW X1 idle vibration?

The causes of BMW X1 idle vibration are severe engine carbon deposits, ignition system issues, or unstable oil pressure. The specific reasons are as follows: Severe engine carbon deposits: The most common cause of car vibration is a dirty throttle or excessive carbon deposits in the fuel injector. When there is too much carbon deposit inside the engine, the gasoline sprayed by the cold-start injector will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts, making it difficult to start and causing idle vibration after cold starts. Ignition system problems: Check the working condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or improper spark plug firing can also lead to such faults. The solution is to check if the spark plugs have excessive carbon deposits and replace them if necessary. Unstable oil pressure: If you have already cleaned the engine carbon deposits, cleaned the throttle, replaced the oil pads and spark plugs, but still notice body vibration during idle, it is recommended to visit a 4S shop to check the fuel supply pressure and the intake pressure sensor. If the fuel pump supply pressure is abnormal or the intake pressure sensor values are incorrect or malfunctioning, it can cause body vibration.
2
5
Share

What are the differences between Mercedes-Benz W204 and W205?

The two generations of products use different powertrains, have different exterior designs, and also feature different interior designs. Below are the specific details: 1. Configuration: The C-Class is one level lower than the E-Class and belongs to the small and medium-sized car category. The CL-Class is a sports sedan with a coupe-like appearance, available in CLS and CLA variants. The CLS is positioned between the E and S classes, while the CLA is comparable to but slightly lower than the C-Class. The G-Class is Mercedes-Benz's king of off-road vehicles, a large and pure off-road vehicle. 2. Mercedes-Benz: Mercedes-Benz is a renowned German automobile brand founded by Karl Benz, who is known as the "father of the automobile" and a pioneer of modern cars. Mercedes-Benz is famous worldwide for its high-quality standards and high-performance car designs and is a very well-known automobile manufacturer.
4
3
Share

Does Tire Size Affect Annual Inspection?

Tire size does affect the annual inspection. If the vehicle's tire size has been changed, it will not pass the annual inspection. The law does not allow arbitrary changes to tire size, as this can impact the vehicle's performance and comfort, and in severe cases, may compromise driving safety and lead to traffic accidents. Here is an introduction to the items checked during the annual vehicle inspection: 1. Exterior Inspection: Primarily checks for any modifications to the vehicle's body, the extent of aftermarket modifications, and ensures all lights are functioning properly. 2. Emissions Test (to obtain the environmental label): Mainly tests the vehicle's exhaust emissions. The owner only needs to wait in the inspection hall. 3. Driving Safety Check: Primarily examines the vehicle's safety performance, typically including speed checks, side-slip tests, chassis inspections, light brightness checks, and full braking system tests. 4. Obtaining the Inspection Certificate: Once the vehicle passes the inspection, the owner can collect the inspection certificate. Vehicle Annual Inspection Procedure: 1. Fill out the form: Locate the annual inspection registration window to submit and review materials. 2. Check for violations: If there are any outstanding fines, they must be paid at the violation inquiry window. 3. Exterior inspection: A technician will inspect the vehicle's exterior, including the engine compartment and VIN (Vehicle Identification Number), and provide a signed inspection approval. 4. Pay the inspection fee: Proceed to the payment window to receive the invoice. 5. Submit materials: All documents are submitted at the registration window, after which the vehicle can proceed to the testing area. 6. Queue for inspection: Follow instructions during the inspection process. Upon completion, a test report will be issued. 7. Finalize the process: Return to the service hall with the test report, submit all required documents, sign where necessary, and hand over the vehicle registration. The clerk will issue the annual inspection sticker and update the inspection date on the registration copy.
7
1
Share

How to Solve the Issue of ETC Not Being Scanned When Exiting the Highway?

If the ETC is not scanned when exiting the highway, there are generally three solutions: first, contact the bank; second, approach the toll station or the highway company; third, call the highway service hotline. As the saying goes, distant water cannot quench present thirst—the simplest and quickest method is to seek help from the toll station staff. Below are the relevant details: 1. Ask the staff to scan: If an ETC vehicle fails to scan successfully when exiting the toll station, it cannot use the ETC lane to enter the highway next time. The solution is simple—just hand the ETC card to the toll station staff for scanning. 2. Consequences of evading fees: If the ETC does not deduct the fee when exiting the highway and the driver chooses to evade payment, they will be added to the ETC blacklist, barred from using highways nationwide, and charged based on the longest distance of the entire highway. 3. Solution: In such cases, drivers should follow the toll station staff's guidance to the MTC or manual lane and pay the toll via card or cash to proceed. 4. Unauthorized scanning: If the ETC is scanned without authorization, drivers can report it to the toll station staff. They will not be charged twice, and the next time they enter the highway via ETC or manual ETC card scanning, the previous transaction information will be overwritten, ensuring normal usage.
14
5
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.