Failure to clean the entire oil circuit will cause thickened carbon deposits on the piston, thickened carbon deposits on the top of the intake and exhaust valves, and excessive impurities and moisture in the fuel tank, causing abnormal combustion of the mixture.
The carbon deposits on the tops of the intake and exhaust valves thicken, and excessive impurities and moisture in the fuel tank cause the mixture to burn abnormally. There will be no obvious feeling at first, and you will find that the jitter is getting bigger and bigger.
Because the combustion space changes after carbon is deposited in the combustion chamber, the compression ratio increases, and normal Roewe Car will explode in advance after entering, that is, the cylinder will burst, causing vibration and shaking, which cannot be detected by any computer.
If the oil pressure is insufficient, the computer can detect it. If there is a cylinder shortage, if the spark plug of a Petrol Car is faulty, if the injector is faulty, the computer can also detect it. If there is a problem with the three-way catalytic converter, it can also be detected. If there is a problem with the sensor, it can still detect it. Therefore, your problem is not an adhesion problem, but a carbon deposit problem, which cannot be detected. At this time, because you have completed all the tests, the remaining cause is carbon deposition, which cannot be detected by the computer. One or two bottles of Siyoupu fuel additive can solve the carbon deposit problem.