What are the symptoms of insufficient cylinder pressure while driving?

[JulianaRose]

If the cylinder pressure is insufficient, the following symptoms may occur while driving: lack of power; excessive smoke from the exhaust pipe; and difficulty starting the engine. Insufficient cylinder pressure is usually caused by air leakage in a certain part of the engine or excessive clearance between the piston and the cylinder wall. The effects of insufficient cylinder pressure include: 1. Burning oil: If the clearance between the piston and the cylinder wall is too large, it may also lead to oil burning. Long-term oil burning can damage the vehicle's catalytic converter and accelerate engine wear. 2. Severe carbon buildup: If the cylinder pressure is insufficient, severe carbon deposits may form inside the engine, which can be quite harmful. Excessive carbon deposits on the piston crown can increase the engine's compression ratio, leading to knocking during operation. Engine knocking may cause connecting rod deformation or piston cracking.