What are the causes of low cylinder pressure?
2 Answers
There are several main reasons for low engine cylinder pressure: 1. Low pressure in a single cylinder: This is usually due to poor valve sealing. 2. Low pressure in two adjacent cylinders: This is typically caused by a faulty cylinder head gasket seal. 3. Low pressure in all cylinders: Inject 20-30ml of engine oil and recheck. If the cylinder pressure increases, it indicates excessive wear of the cylinder, piston, or piston rings, or poor piston ring sealing. If the pressure remains unchanged, it suggests a faulty cylinder head gasket or valve seal, or a blocked intake manifold. 4. Low pressure in one or some cylinders: This indicates poor combustion in these cylinders, often due to excessive carbon deposits.
Low cylinder compression is a common headache. As a truck driver for over a decade, I've encountered this issue many times. The main causes include worn piston rings failing to seal properly, leading to compression leaks; valves that don't seal tightly or get stuck due to carbon buildup; blown cylinder head gaskets causing air or coolant leaks affecting pressure; and cylinder wall scoring or piston damage. A compression tester can easily diagnose these problems. Drive gently - avoid aggressive high-RPM operation, change oil regularly, and clean carbon deposits periodically. Delaying repairs only increases fuel consumption, reduces power, and ultimately leads to costly engine overhauls. Experience teaches us: early detection and timely maintenance ensure both safety and cost-efficiency.
