What Are the Causes of Excessive Cylinder Pressure?
3 Answers
The main causes of excessive cylinder pressure are the following two points: 1. Excessive carbon deposits in the combustion chamber; 2. During repairs, excessive grinding of the cylinder head and cylinder block mating surfaces leads to a reduced combustion chamber volume and an excessively high compression ratio. Below are specific details regarding cylinder wear: 1. Mechanical wear. When the piston is at top dead center, the high-temperature gas explosion pressure is at its maximum, causing increased piston ring pressure on the cylinder wall, increased friction, and destruction of the lubricating oil film. The cylinder wall corresponding to the first piston ring experiences the most severe wear. 2. Corrosive wear. Organic acids and acidic oxides (which dissolve in water to form mineral acids) generated during the combustion of the air-fuel mixture corrode the cylinder surface, leading to corrosive wear. The upper part of the cylinder block is not fully covered by the lubricating oil film, making corrosion more severe. 3. Abrasive wear. Dust from the air, mechanical impurities in the lubricating oil, and wear particles in the engine enter between the cylinder walls, causing abrasive wear. Dust from the air is drawn into the upper part of the cylinder, and its sharp edges result in the greatest wear in the upper cylinder section.
As an ordinary car enthusiast, I've personally experienced excessive cylinder pressure. At that time, my old car suddenly had poor acceleration and was smoking. After taking it to the repair shop for inspection, the problem was identified. Common causes include worn or failed piston rings, where leaking compression gases actually cause pressure buildup; excessive carbon deposits reducing compression space and sharply increasing pressure; clogged air filters restricting airflow and creating pressure imbalance; and engine overheating causing metal expansion and poor sealing. These issues can lead to soaring fuel consumption, engine shaking, or even cylinder explosion. I later learned that regular maintenance is key—changing filters every 10,000 km, cleaning throttle carbon deposits, and monitoring the coolant temperature gauge can effectively prevent such problems. I remember spending a lot of unnecessary money on that repair—early detection and treatment save both hassle and costs. Avoiding prolonged idling and regularly checking engine condition are crucial for daily driving.
I usually enjoy studying little-known facts about cars, and excessive cylinder pressure is no small issue. Piston ring leakage is quite common, where escaping gases can actually increase pressure; carbon buildup raises the compression ratio leading to sudden pressure spikes; a clogged air filter restricts airflow in and out, worsening pressure; cooling system failures like a stalled fan cause engine overheating and thermal expansion pressure. After modifying my car, I've experienced this more deeply - improper operations like improperly matched turbocharger adjustments can cause this. Consequences include increased noise and fuel consumption, even internal component damage. My advice: don't delay, regularly check pressure parameters or clean carbon deposits, use appropriate engine oil and fuel additives for prevention. Develop driving habits that minimize short trips to reduce carbon formation.
