The engine's head gasket is a core sealing component located between the cylinder head and cylinder block. Its primary function is to isolate fluids from different chambers and ensure engine airtightness, making it a critical component for preventing engine leaks.

Its function is directly related to the proper operation of the engine. Damage can cause serious malfunctions, such as coolant entering the oil passages or cylinders.

1. Core Function

Sealing High-Temperature, High-Pressure Gas: Combustion within the cylinder generates extremely high pressures and temperatures. The head gasket tightly fits the joint between the cylinder head and cylinder block, preventing gas from leaking from the combustion chamber to the outside or other chambers.

Isolating Coolant from Oil: The engine has separate coolant passages (for cooling) and oil passages (for lubricating components). The head gasket completely isolates these two fluids, preventing coolant from mixing with the oil (causing oil emulsification failure) or oil from seeping into the coolant (impairing heat dissipation).

Maintaining the Independence of Each Chamber: Ensures that the oil, water, and combustion chamber passages in the cylinder head and cylinder block are sealed and prevent intercommunication, ensuring the proper functioning of the engine's cooling, lubrication, and combustion systems. 2. Key Performance Requirements
High-Temperature and High-Pressure Resistance: Required to withstand combustion temperatures exceeding 1000°C and pressures of tens of megapascals within the cylinder for extended periods, a metal sandwich structure (such as steel sheet + asbestos/graphite composite) is often employed.
Good Sealing and Adhesion: The material must exhibit a certain degree of elasticity to compensate for minor deformations at the joint between the cylinder head and cylinder block, ensuring a seamless seal.
Corrosion and Aging Resistance: Required to withstand long-term immersion in coolant and engine oil, and not susceptible to loss of sealing performance due to chemical corrosion or high-temperature aging.
3. Common Consequences of Damage
Engine Power Loss: Gas leakage can lead to insufficient cylinder pressure, reduced combustion efficiency, weak power, and lackluster acceleration.
Abnormal Coolant Consumption: Coolant seeping into the cylinder and burning can cause a rapid decrease in coolant, and white mist may be emitted from the exhaust pipe.
Engine Oil Emulsification: When coolant mixes with engine oil, the oil becomes milky and emulsified, losing its lubricating properties. In severe cases, this can cause wear on core components such as the crankshaft and camshaft. If you need information on cylinder head gasket replacement for different models, would you like me to help you compile a guide to the key steps and pitfalls of cylinder head gasket replacement? It covers key points like pre-installation cleaning and torque requirements to avoid further damage after replacement.