Should PDI Inspection Be Conducted in Front of the Customer?

What Are the Common Engine Faults and Their Causes?

Eight common engine faults and their causes: 1. Engine cold start shaking: The engine shakes during cold start idle but returns to normal after warming up. The main reason is excessive carbon deposits inside the engine. During cold starts, the fuel injected by the injectors is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture, making it difficult to start. Only after the carbon deposits are saturated with fuel does the engine start easily. Once started, the fuel adsorbed on the carbon deposits is reabsorbed into the combustion chamber, enriching the mixture. The fluctuating air-fuel mixture causes idle shaking after a cold start. Another cause could be faults in spark plugs or ignition coils. 2. Engine hot idle shaking: The engine shakes during hot idle. There are many causes for this, the most common being engine misfire. Generally, check the spark plugs, ignition coils, fuel injectors and fuel system, exhaust blockages, fuel grade compatibility, carbon deposits in the engine, carbon buildup in the throttle body, and the firmness of engine mounts. 3. Engine abnormal noise: Engine noises can be categorized into cold and hot engine noises. Cold engine noise: Often caused by oil draining back into the oil pan after prolonged parking, preventing the oil pump from establishing oil pressure and forming an oil film immediately during a cold start, leading to inadequate lubrication and noise. Hot engine noise is usually more serious and harder to diagnose, often due to piston slap or knocking. Crankcase ventilation leaks can also cause loud noises, and the car belt may produce noise at certain speeds, usually due to slippage or aging. 4. Engine carbon deposits: Carbon deposits form mainly from incomplete combustion during engine operation, along with gummy substances produced by impurities in fuel and oil, accumulating over time. 5. Dirty throttle body: The main cause of carbon buildup in the throttle body is the reciprocating airflow during engine intake and exhaust strokes. Not only does it draw in air during intake, but gas reflux during valve overlap can also lead to carbon deposits. Additionally, the crankcase forced ventilation in front of the throttle body reintroduces exhaust gases into the combustion chamber via the intake valve, directly causing the throttle body to become dirty. 6. Engine oil burning: The causes of oil burning are varied, ranging from manufacturer specifications to component damage. Some vehicles burn oil almost as much as they consume fuel. Excluding manufacturer issues, new cars rarely burn oil (after the break-in period). Common causes include incorrect oil grade, aging or damaged valve seals, piston ring sealing issues leading to oil blow-by, damaged crankcase ventilation or oil separator, and cooling/lubrication issues in the turbocharger. 7. Engine oil leaks: There are many causes of oil leaks, most commonly due to aging gaskets. Common leak points include aging or damaged oil pan gaskets or loose bolts, loose drain plugs, missing gaskets, damaged threads, aging timing cover gaskets, leaking valve cover gaskets, front and rear crankshaft seal leaks, aging oil cooler gaskets, and leaking oil filter housing gaskets. 8. High engine coolant temperature: High coolant temperature is indicated by temperature warnings or boiling over. Common causes include faulty thermostats disrupting the cooling cycle, dirty radiators reducing efficiency, insufficient coolant, trapped air in the cooling system, faulty electric fans, water pump failures, or faulty temperature sensors.

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What does the sun exclamation mark mean in a car?

The sun with an exclamation mark in the middle is the brake pad warning light, indicating a brake pad fault, which serves as a reminder to replace the brake pads. The warning will also appear when the front brake pads are nearing their wear limit. More information about the sun exclamation mark in cars is as follows: 1. Introduction: The car dashboard is a device that reflects the working conditions of various vehicle systems. Common indicators include the fuel indicator, washer fluid indicator, electronic throttle indicator, and front/rear fog light indicators. Dashboards vary between different car models. 2. Causes of brake pad failure: If the brake warning light comes on during a long trip, it indicates that the brake fluid level is insufficient, and there may be a leak in the brake system.

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How often should the engine be serviced?

The maintenance interval for an engine is typically every six months or 5,000 kilometers. The specific maintenance schedule should be determined based on the vehicle's usage habits and conditions. Additionally, the type of engine oil used affects the maintenance interval. 1. If mineral oil is used, the maintenance interval is 5,000 kilometers. 2. If semi-synthetic oil is used, the maintenance interval is 7,500 kilometers. 3. If full synthetic oil is used, the maintenance interval is approximately 10,000 kilometers. Five key points for engine maintenance: 1. Use the appropriate grade of engine oil and change the oil and filter regularly (every 5,000 kilometers). 2. Frequently maintain the air filter and replace it periodically (every 20,000 kilometers). 3. Regularly clean the fuel system and replace the fuel filter periodically (every 30,000 kilometers). 4. Periodically service the radiator cooling net (every 30,000 kilometers). 5. Replace the spark plugs periodically (every 40,000 kilometers or based on driving conditions).

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What Does a Vehicle Powertrain System Malfunction Mean?

Vehicle powertrain system malfunction refers to a failure occurring in the entire mechanical arrangement process where the power generated by the engine is transmitted through a series of power transfers and finally reaches the wheels. Below are detailed explanations: 1. Causes of malfunction: Incorrect ignition timing, premature ignition causing early combustion and detonation of the combustible mixture; spark plug misfire or weak spark due to faults in the ignition system; cylinder compression pressure issues, severe wear of pistons, piston rings, and cylinders leading to increased clearance between them, reduced sealing performance, cylinder head leakage, and decreased cylinder compression pressure; poor sealing of the crankcase causing air leakage and reduced suction. 2. Solutions: Check if the air filter is clogged and clean it if necessary. Check the throttle opening—when the accelerator pedal is fully depressed, the throttle should be fully open; otherwise, adjust its cable or perform learning for the pedal position sensor and throttle position sensor. Take the vehicle to a repair shop for servicing.

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Why Does a Car Horn Go Mute?

Car horns go mute primarily due to poor contact at the horn terminals. Here are the relevant details: 1. Cause: Frequent and prolonged use of the horn can cause the horn contacts to burn and corrode, creating impedance. This reduces the current in the electromagnetic coil, weakening its magnetic force, which in turn loses the attraction needed to vibrate the diaphragm, resulting in a hoarse horn sound. 2. Function of the Horn: Designed to alert others, the horn must produce a loud sound. If it sounds hoarse, it may fail to attract the attention of pedestrians and other vehicles, potentially leading to traffic accidents. 3. Maintenance Tips: Avoid pressing the horn for extended periods—preferably no longer than 10 seconds—to prevent contact burning and horn damage. Keep the horn exterior clean and avoid direct water spray during car washing to prevent water ingress, which can mute the horn. If water does enter, promptly dry it with an air gun. Regularly check the horn's fixing screws to ensure proper grounding and inspect the engine's output voltage to prevent damage from excessive voltage (which can burn the horn contacts) or abnormal sound due to low voltage. Avoid modifying the horn arbitrarily; if modifications are necessary, consult a professional to prevent incorrect placement of metal and insulating pads, which can cause horn malfunctions.

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What are the practical features of the Avalon?

Toyota Avalon's practical features are as follows: (1) Center console buttons: 1. Hazard warning lights (commonly known as double flashing lights): Used to warn surrounding vehicles to prevent rear-end collisions. 2. Internal/external circulation: The difference between internal and external circulation is: Internal circulation: Air is always provided from inside the vehicle. External circulation: Allows outside air to enter and replace the original air inside the vehicle. 3. Temperature zone synchronization: The function of temperature zone synchronization is that only the driver's temperature needs to be changed, and other temperature zones will follow the same change. After turning off this temperature zone synchronization, each zone can be set individually to meet the needs of passengers in different positions. (2) Door buttons: On the Toyota Avalon driver's door: 1. Rear window lock button. 2. One-touch up/down control switch for all four windows. 3. Adjustment switch for the exterior rearview mirrors (angle, folding). 4. Central locking button. (3) Roof buttons: 1. Driver's reading light. 2. Front passenger reading light. 3. Vehicle lighting switch. 4. Sunroof switch.

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Should PDI Inspection Be Conducted in Front of the Customer?

What Are the Common Engine Faults and Their Causes?

What does the sun exclamation mark mean in a car?

How often should the engine be serviced?

What Does a Vehicle Powertrain System Malfunction Mean?

Why Does a Car Horn Go Mute?

What are the practical features of the Avalon?

What to Do When a Mazda Car Key Runs Out of Battery?

How Long Does It Take to Repair a Car Dent?

What Causes a Gasoline Water Pump to Automatically Shut Off?

Why can't the Haval H6 detect the key?