MG 3 15,000 km machine makes a strange noise

15 automatic MG 3, the engine is abnormal, the sound is very loud, and it is suspected that the timing is jumping. 15 automatic MG 3 ( Check price |.)Detailed explanation of the model), the engine is abnormal, the sound is very loud, and it is suspected that the timing is skipping. Engine noise can be roughly divided into engine noise during cold start, engine noise during rapid acceleration, and engine noise at idle.

1. Abnormal noise caused by aging or loosening of the machine foot pad. The foot pad, also known as the chicken paw pad and the tripod, is generally installed in the middle of the engine and the body, connecting the body and the engine, and playing the role of fixing the engine. And its most important role is to play the effect of cushioning and shock absorption.

Once the machine mat is aged or loose, the engine shake will be severe, from Because you can't see the actual car, you can't accurately judge the fault, it is recommended that you contact your local 4S shop for testing and maintenance. @2019

Perhaps the adjusted valve clearance during maintenance has changed or been improperly adjusted; The valve adjustment screws are worn and skewed, the lock nut is loose, or the valve clearance is too large or inconsistent.

On the issue of abnormal noise, it is difficult for ordinary car owners to distinguish which ones are fault abnormal noises and which ones are reasonable abnormal noises. Only nearly 20% of the vehicles that went to the repair shop to detect abnormal noises really had problems. In the case of a turbocharged engine, there is a must be a difference between the sound and the sound of a naturally aspirated engine; Models with engine guards may also make noises due to friction; After some car owners come into contact with different cars, it is likely that they lack their own understanding of mechanical knowledge, so they can distinguish the abnormal noise of the car and avoid wasting time and energy.

How to identify the sound of a car:

In practice, due to the limitation of the working potato liquid, it is difficult to measure the sound of the car with special instruments, and the sound of the car can only be described and compared with the judgment of the sound in daily life. For example, the "rattle" sound caused by the dry friction of the bearing, and the "click" sound similar to the small hammer hitting the cement floor caused by the excessive valve clearance.

1. Correctly distinguish between normal and abnormal sounds.

The vibration of each mechanism in the work of the car will emit a variety of sounds, but the sound does not mean that the car is faulty, in order to avoid unnecessary disassembly, we must first distinguish between normal sound and abnormal noise. The normal vibration sound of each system component (such as the noise on the surface of the engine), the impact sound of the gear when shifting, the air intake sound and exhaust sound of using gas as the working source, and the gear meshing noise are all normal sounds. Abnormal noise (abnormal noise) can be divided into slight noise, general noise and malignant noise according to the impact on the performance of the car.

Slight noise, such as the flashover sound of high-voltage electric leakage, the slight loose sound of rolling bearings, etc., the general volume is small, the degree of wear of the parts is not large, and there is no significant change for a long time, and this kind of fault can still maintain the normal operation of the car without repair.

3. When diagnosing abnormal noise of automobiles, attention should be paid to creating good auscultation conditions for good volts, and trying to eliminate the interference of other noises, so as to avoid amplifying the noise in the shadow position, or reducing the noise in the way of single-cylinder fire cut-off, so as to meet the needs of diagnosis. The auscultation site should be kept quiet to minimize human interference.

A cause that cannot be underestimated is "carbon deposition", which will cause insufficient combustion of gasoline, so that the engine will have the problem of shaking and abnormal noise. The impact of engine carbon deposition on the car is quite large, first of all, to reduce the engine power, that is, to make the power output uneven and gradually decay, in other words, more and more powerless. The second is to increase fuel consumption and increase your financial burden.

The third is the difficulty of cold start, that is, the difficulty of ignition, it is not easy to get on the car, and finally the serious carbon deposition in the combustion chamber will also cause cylinder detonation, and there will be a sound of low-speed acceleration, which will cause damage to the piston and crankshaft, thereby seriously affecting the safety of the car. Then there is the excessive discharge, which not only fails the annual inspection and inspection, but also directly aggravates the harm of polluting the environment.

There is another reason: the throttle valve is faulty. Both of these problems can cause engine shake and unstable revs (German Marty, professional technicians can solve problems for you).

First of all, you need to check where the abnormal engine noise is, some of the noise is the sound of a normal car starting.