The car engine is not running smoothly, what is the reason for shaking?

The main causes of unstable jitter at idle:

1.Serious engine carbon deposits: Cars always have the problem of carbon deposits, including cylinder carbon deposits, throttle carbon deposits, spark plug carbon deposits, intake carbon deposits, etc.

When the engine has too much carbon deposit, it will affect the ignition energy, air intake efficiency and air-fuel ratio of the car, resulting in the unstable power output of the car, and the phenomenon of idle speed and acceleration jitter appears.

2.Unstable oil pressure: If you have cleaned the engine carbon deposits, cleaned the throttle, replaced the oil gasket and spark plug, etc.

And when idling, you still find that the body shakes, it is recommended that you go to the 4S shop to check whether the oil supply pressure and intake pressure sensor are normal, if the oil pump supply pressure is abnormal, or the intake pressure sensor value is wrong, and the work is not good, it will cause the body to shake.

3.Engine cylinder shortage: Engine cylinder deficiency mainly refers to the engine one or more cylinders are not working properly, which is generally manifested as:

The exhaust fumes coming out of the car are obviously intermittent, and the exhaust pipe shakes violently, and the engine shake can be clearly felt, sometimes accompanied by abnormal noises. This is mostly related to ignition coil failure.

4.Aging of engine parts: Shake in the car is also associated with the aging of the engine feet (also known as claw pads).

The engine foot is actually the shock absorber system of the engine. The engine feet are responsible for absorbing slight vibrations when the engine is running. If there is a problem with the engine base, these vibrations can be transmitted to the steering wheel and cab, causing vibrations at idle.

Solution; The best way is to clean the oil circuit, clean it regularly, and use PNF fuel additives to solve the above problems caused by carbon deposits. The fuel quality is not very good or the initial fuel of the new car is stored for too long, resulting in a rapid increase in the colloidal composition of the oil circuit, which will continue to pollute the fresh fuel and cause no good fuel to participate in combustion in the later stage, and the carbon deposition exceeds the standard, which is especially common for China VI vehicles. We can only gradually alleviate most of the problems by maintaining clean oil circuits.

The idle state refers to the working condition of the engine when it is idling, that is, when the engine is running, the accelerator pedal is completely relaxed, and the engine is in the idle state. The speed at which the engine is idling is called idle speed, which is the minimum speed at which the engine can maintain normal operation without external output. Engines with good working performance generally have an idle speed of 550-800 rpm.

Unstable idle speed is in the idle state, the speed fluctuates high and low and changes greatly, which is the most common fault of the engine, and the main common reasons are:

1) The idle switch is not closed.

Diagnosis method: Turn on the air conditioner and turn on the steering wheel when idling, and the engine speed does not rise, which can prove to be this fault.

Exclusion: Adjustments, repairs, or replacements of throttle position sensors.

2) Idle control valve (ISC) failure.

Diagnostic method: Check the actuation sound of the idle control valve, if there is no actuation sound, the idle control valve is faulty.

Troubleshooting: Clean or change the idle control valve, and use a special decoder to set the idle speed basically.

3) Air leakage in the air intake line.

Diagnostic Method: If you hear a snorting sound of a leak in the intake pipe, it is evidence of a leak in the air intake system.

Troubleshooting: Find leaks, reseal or replace phase parts.

4) Injector dripping or clogging.

Diagnostic method: Use a stethoscope to check whether the injector makes a "click" actuation sound or measure the fuel injection volume of the injector, if the injector does not make a sound or the fuel injection volume exceeds the standard, the injector is faulty.

Troubleshooting: Clean the injectors, check the amount of fuel injected into each injector and confirm that there is no clogging or dripping.

5) Exhaust system blockage.

Diagnostic method: Use a vacuum gauge to detect the px, if the px is low and the acceleration is often accompanied by the phenomenon of stuffiness, it can be determined that this fault is the fault.

Troubleshooting: Replace the three-way catalytic converter.

In addition to the above fault causes, there are many faults that can also cause idle abnormalities, including: ECU failure; main oxygen sensor circuit; EFI main relay circuit; Standby power circuits; cold-start injector circuitry; Variable resistor resistance for gas mixture; fuel quality; Vacuum leakage in the inlet pipe; clogged air filter; Poor cylinder compression, etc.

There are many reasons for engine shaking, sensors, mixtures are too thick or too thin, lack of cylinders, dirty throttle valves, etc. will cause shaking.

The engine runs unsmoothly and the jitter is caused by uneven wear of the distributor cam, loose and deflected distributor shaft, or poor spark plug work

The phenomenon of engine shaking will involve many reasons, such as excessive carbon deposition in the intake system such as throttle and idle valve, poor fuel injection atomization of the fuel injection nozzle, and poor working performance of the ignition system, which is mainly directly related to the working performance of the spark plug, high-voltage line and ignition coil

1. The lack of cylinders in the engine, the lack of cylinders in the engine mainly refers to the fact that the engine has one or more cylinders that are not working normally, which is generally manifested as: the exhaust gas flow discharged by the car has obvious intermittent intermittentness, and the exhaust pipe shakes violently, and the shaking of the engine can be clearly felt, sometimes accompanied by a sudden sound. This is mostly related to ignition coil failure;

2. Carbon deposition problems include cylinder carbon deposition, throttle carbon deposition, spark plug carbon deposition, intake carbon deposition, etc., these positions are just closely related to the power output of the engine, when the carbon deposition inside the engine is excessive, the ignition energy of the car is reduced, and the air intake efficiency decreases, which eventually leads to the engine shaking, acceleration weakness symptoms;

3. Fuel system failure, adding inappropriate fuel labels (for example, No. 93 to No. 90), resulting in a decrease in the output power of the car and a decrease in power; Or due to the blockage of the vent of the fuel tank cover, the fuel tank switch, the fuel filter and the oil pipe between the fuel tank and the carburetor are partially blocked, which cannot meet the required oil volume, resulting in the mixture being too thin and the engine shaking;

4. Air intake system failure, air is one of the power of the engine, if the air filter is not cleaned in time for a long time, the lack of air volume will cause the combustible mixture to be too thick, so that the engine power decreases; If it is a vehicle with a turbocharger, the failure of the supercharger will also cause the engine to shake during acceleration;

5. Cold start, when the car starts cold, the engine lubrication effect is relatively poor, the oil fluidity is poor, and it is also relatively viscous, so there will be abnormal sound of mechanical wear, as well as cold start, the coolant temperature is relatively low, the mixture is relatively thick, and insufficient combustion will cause the engine to shake and, this is generally a normal phenomenon, and it will get better after the hot car.

The reasons for the severe engine shaking: 1. The carbon deposition of the engine is more serious, which causes the engine to shake at the speed of thought, the engine idle jitter is irregular, sometimes for several days, sometimes it will get better, at this time, the engine carbon deposition problem should be considered 2, there is a problem with the ignition system, if it is a fault caused by the connection, you can repair it yourself. It should be noted that the car will not produce engine speed shake after the end of smooth driving, in this case, it is likely to be a fault caused by the unstable oil pressure of the car, and it is recommended that you repair it in time.

The specific causes and solutions of unstable idling after the car starts:

1.Intake manifold leakage: When the air, gasoline vapor and combustion exhaust gases that should not enter the intake manifold, the mixture is too thick or too thin, resulting in unstable idling of the car.

Solution: Check the manifold and replace it in time if there is any air leakage.

2.Excessive carbon deposition on the throttle: excessive carbon deposition on the throttle and surrounding air intakes, and changes in the cross-sectional area of the airway, which makes the control unit (check the transaction price|Matching|preferential policies) cannot accurately control the idle air intake, which also causes the mixture to be too thick or too thin, resulting in unstable car idling.

Solution: The best way is to clean the oil circuit, clean it regularly, and use PNF fuel additives to solve the problems caused by carbon deposits. The fuel quality is not very good or the initial fuel of the new car is stored for too long, resulting in a rapid increase in the colloidal composition of the oil circuit, which will continue to pollute the fresh fuel and cause no good fuel to participate in combustion in the later stage, and the carbon deposition exceeds the standard, which is especially common for China VI vehicles.

We can only gradually alleviate most of the problems by maintaining clean oil circuits.

The car engine is not running smoothly, what is the reason for shaking? Is it engine shaking, or body shaking, if it is body shaking, it may be that the engine is not very good, if it is engine shaking, it may be caused by a cylinder not working very well.

Hello dear! Thank you for waiting, if the engine is shaking at idle after the engine temperature rises, there are two main reasons to consider. The first aspect needs to be considered, it is caused by the dirty throttle of the engine, and the engine idle speed drops at this time, so if the air intake is insufficient, it will cause the engine idle shake to be unstable, and this cleaning throttle can be done.

The second aspect is to consider that the engine mixture is abnormal, which needs to use a decoder to read the data stream of the engine to see if the engine mixture concentration is normal, if the concentration is dilute, check the fuel pressure, check whether the intake air leaks. Kiss! I hope mine can help you.

It is normal for a car with a piston engine to have a slight jitter, and the fewer the number of cylinders of the engine, the greater the jitter, the lower the speed, the greater the jitter, and the better the more cylinders, which is also related to the arrangement of the cylinders.

Check whether the spark plug should be replaced, whether the throttle is too dirty, whether the cylinder line is aged, whether the fuel injector is dirty, and whether the gasoline and engine oil used are all related.

"Unstable idling" throttle has carbon deposits to be cleaned. The engine shakes very gasoline and has something to do with the poor oil quality.

When the speed is small, just turn it up! Jitter is also because of this!

1. Dirty, abrasive damage, incorrect installation of mechanical parts, etc., resulting in changes in the power of individual cylinders, resulting in unbalanced power of each cylinder, resulting in unstable engine idling.

2. The engine electronic control system is abnormal, resulting in poor combustion of the mixture, which makes it difficult to balance the power of each cylinder and makes the engine idle unstable.

3. There is too much carbon and dirt in the throttle and the surrounding air intake, and the cross-sectional area of the air channel changes, which makes the control unit unable to accurately control the idle air intake, resulting in the mixture being too thick or too thin, and making the combustion abnormal.

4. The fuel pressure is too low, which directly leads to the mist sprayed out, and the spray quality is poor, and only part of the oil droplets appear at the fuel injection port. The main manifestation is that the mixture emissions are too thin, resulting in unstable engine idling and low speed, often accompanied by a lack of fire.

5. The internal fuel injection of the injector is small, showing fog and smoke outside, which will lead to insufficient power generated by each part of the cylinder, resulting in abnormal engine starting.

6. The fault of the sensor circuit may be caused by short circuit, open circuit or the sensor is not grounded. These faults cause errors in the commands issued by the control unit, resulting in inaccurate measurements of the injected volume and thin or dense mixtures.

loose intake manifold clamp or cracked hose;

Unstable engine idling is mainly due to the following aspects of the car:

1. Failure of the air intake system.

1. Leakage of intake manifold or various valves.

When the air that should not enter, gasoline vapor, and combustion exhaust gas enter the intake manifold, the mixture is too thick or too thin, and the engine burns abnormally.

2. Excessive fouling of the throttle and inlet tract.

Common phenomena are: throttle valve oil or carbon deposits; There is oil and carbon deposits in the air intake tract around the throttle; Idle stepper motors, duty cycle solenoid valves, and rotary solenoid valves have oil stains and carbon deposits.

3. Failure of idle air actuator.

Inaccurate idle air control due to a faulty idle air actuator. Common causes are: throttle motor damage or card issuance; Idle stepper motors, duty cycle solenoid valves, rotary solenoid valves are damaged or hairpinned.

4. The air intake is inaccurate.

Common phenomena are: air flow meter or its line fault; Failure of the inlet pressure sensor or its wiring; The plug of the engine control unit is in poor contact due to water ingress or internal computer failure.

Second, the fuel system failure.

1. Injector failure.

The uneven amount of fuel injection and the mist of the injector cause an imbalance in the power emitted by each cylinder. Common causes are: clogged injectors, poor sealing, and linear fuel injection.

What to do if the engine is shaking at idle.

It mainly introduces the engine idle motor throttle is too dirty, and the idle speed is unstable.

Cause analysis: It may be that the spark plug is faulty or the ignition time is too early. If it is not the fault of the spark plug, it can be judged that the ignition time is too early.

Solution: When the above faults occur, they should be repaired in time to the repair shop.