The performance excellence of BMW vehicles stems from their engines. The head gasket in the engine is a crucial sealing component that is positioned between the engine block and the cylinder head. Its functions include;
- It contains and holds the extreme heat and pressure generated during the combustion cycle within the cylinder and ensures the maximum amount of power is transferred to the piston.
- It seals the coolant and oil passage that runs between the cylinder head and the engine block, preventing the mixing of vehicle fluids and fuel mixture.
Common Causes Behind the Damage of the Head Gasket in the BMW Engine
The damage to the head gasket of the engine is almost always attributed to a symptom of another vehicle malfunction. Some common causes include;
Overheating
This is the most common cause of head gasket damage in BMW engines. When the BMW engine overheats, the cylinder head expands at a different rate than the engine block, as they are made up of different materials. This causes the head gasket seal to become damaged.
Detonation/Engine Knock
Engine knock/detonation is the sudden, excessive, and uncontrollable combustion of the fuel mixture in the engine cylinder, emulating an explosion. This creates an extreme amount of heat and pressure that the head gasket couldn’t contain. This causes damage to the gasket, forming cracks and breaches.
Age and Mileage
After thousands of miles and numerous heat cycles, the material of the head gaskets degrades and loses its sealing ability due to becoming brittle. This makes the gasket prone to failure, as it can easily cause leaks and cracks.
Improper Installation
The gasket operates in a high-heat and high-pressure environment within the BMW engine, and it requires a multi-stage torquing sequence for proper installation. If the gasket is not installed correctly or old bolts are reused during installation, it faces uneven clamping forces, creating weak spots. These spots then create cracks under high pressure.
Impact of a Damaged Head Gasket in BMW
The damage to the head gasket allows for the intermixing of engine oil, coolant, and fuel in a high-pressure environment. This causes;
- Entry and burning of coolant in the combustion chamber, causing a copious amount of white smoke from the exhaust.
- The creation of air pockets in the coolant lines prevents coolant flow, causing the engine to overheat.
- Mixing engine oil and coolant causes the emulsification of oil, damaging its lubricating capacity.
- Low levels of engine oil and coolant are indicated on the dashboard.
- The engine misfires due to compromised combustion in the cylinder.
Repair and Maintenance of the BMW Head Gasket
Repair of the engine head gasket in a BMW begins with a thorough diagnosis of the issue. A visual inspection of the oil and coolant condition is done. Then, more sophisticated tests, such as a cooling system pressure test, chemical combustion leak test, and cylinder-leak down test, are conducted to identify the cause and origin of the issue.
The repair for this issue involves replacing the old and damaged head gasket with a new, OEM-made head gasket. This process involves draining old fuel, disassembling the engine, replacing gaskets, torquing components, and reassembling the engine, followed by the appropriate fluid refill. Additionally, the engine components are inspected and repaired while the module is disassembled to rectify the damage caused by the faulty head gasket.
Beyond repair, several maintenance steps can be taken to keep the BMW engine head gasket healthy and preserve the engine’s health and drivability. These include timely maintenance, proactive component replacement at appropriate mileage intervals, regular checks of oil and coolant levels and conditions, addressing temperature spike issues, and addressing small leaks.
Repairing the BMW Head Gasket at Heynneman European in San Rafael
Heynneman European is 
the premier auto repair and service shop in San Rafael, specializing in servicing European models such as Audi, Porsche, Volkswagen, Mercedes, Volvo, and BMW, and providing precise and impeccable service. Our technicians have extensive experience, deep expertise, and the latest factory training when it comes to European vehicles, such as BMW.
We possess factory-grade diagnostic and repair tools, and use OEM parts and fluids for all our repairs, ensuring your BMW receives the best service for its head gasket damage. Our service center is AAA certified and offers amenities such as a complimentary loaner vehicle and comfortable waiting rooms, ensuring you receive the best repair experience. We provide a 24-month/24,000-mile nationwide warranty on our work.
Located at 3155 Kerner Blvd., San Rafael, we also extend our services to surrounding areas, including Corte, Fairfax, Kentfield, Larkspur, Mill Valley, and San Anselmo.
