What situations can cause excessive cylinder pressure?
2 Answers
Causes of excessive cylinder pressure: 1. Increased carbon deposits in the combustion chamber reduce the combustion chamber volume and increase the compression ratio, creating a false impression of high cylinder pressure; 2. Overly rich air-fuel mixture in the combustion chamber or excessively low engine temperature, as well as poor exhaust flow or clogged catalytic converter can also lead to excessive cylinder pressure; 3. High or low cylinder pressure directly affects the temperature at the end of compression. If the compression pressure is high, the temperature of the compressed air-fuel mixture or pure air will also rise. In this case, gasoline engine fuel is more easily ignited by the spark plug, while diesel engines may experience spontaneous combustion.
In my years of car repair experience, the most common causes of excessive cylinder pressure include uncontrolled combustion systems, such as when detonation occurs and the cylinder pressure rises sharply. This is usually caused by advanced ignition timing or low fuel octane. Secondly, cooling system failures, such as clogged radiators or insufficient coolant, can cause the cylinder block to overheat and expand, increasing pressure. Additionally, issues with the intake system, such as an overloaded turbocharger introducing excessive air and fuel, can also intensify combustion. Valve failures, like a stuck exhaust valve that doesn't close, can cause gas buildup and pressure accumulation. To prevent this, regularly check the condition of the spark plugs and coolant levels, avoid prolonged high-speed driving, and use diagnostic tools to monitor engine parameters when necessary. Long-term neglect can lead to piston ring damage, cylinder wear, or even engine failure, which is not worth it.
