What Causes High Cylinder Pressure?
2 Answers
Excessive carbon deposits inside the cylinder, cylinder gasket being too thin, excessive grinding of the cylinder head. Below is more information about cylinder pressure: 1. Impact: Excessively high pressure and temperature can easily cause detonation and pre-ignition, which are extremely harmful faults. In severe cases, it can lead to engine stalling or failure to start. 2. Pressure values: The normal pressure range for large vehicles is 6 to 8 kg, while for small cars, it is normal to be above 8 kg. If the pressure is below the normal range, it can be determined that the engine has a fault. For a four-cylinder engine, as long as the cylinder pressure is not less than seven pressures, it is within the normal range. Not every engine is the same; Japanese cars typically have around 1100 KPa, while European and American cars are around 1200-1300 KPa. Modern direct-injection engines tend to have even higher pressures.
Having worked in car repair for decades, there are several key reasons for high cylinder pressure: First, piston rings aging or carbon buildup causing them to stick and harden, which increases the compression ratio; second, improper valve adjustment, such as too small a gap or erosion, leading to incomplete closure and less compression gas leakage, thus higher pressure; third, excessive carbon buildup in the combustion chamber reducing space and naturally increasing pressure; also, too much fuel injection or early ignition causing premature combustion and rising compression pressure. Expanding on this, the issue can range from minor to severe. Long-term neglect can lead to excessive engine load and accelerated wear. I recommend regularly checking with a cylinder pressure gauge; normal values should be within the 8-12 atmospheric pressure range. If it's high, promptly investigate the root cause to prevent engine failure before thick smoke appears. Such mechanical faults should be repaired early to save money and hassle. Overall, paying attention to abnormal noises or hard-starting signals during daily driving for early prevention is always wise.
