Fluorocarbon Rubber (FKM/Viton): Resistant to high temperatures (-20°C to 250°C), oil, and chemicals, ensuring long-term sealing performance.
Metal Skeleton: Typically stainless steel or zinc-plated steel for structural strength and stability.
Auxiliary Coating: Some models may feature a PTFE (Teflon) coating to reduce friction and extend valve guide life.
OEM Standards: Complies with BMW’s original material specifications and is compatible with BMW engine oils (e.g., BMW LL series).
Post-Curing: Eliminates internal stress, enhancing elasticity and durability.
Laser Inspection: 100% dimensional check of the sealing lip (tolerance ±0.05mm) for proper valve stem fit.
Surface Treatment: Anti-corrosion coating on metal parts; rubber surfaces are burr-free.
Replacement Steps (Professional Tools Required):
Remove the valve cover, camshaft, and use a valve spring compressor to release the valve locks/springs.
Removing Old Seal:
Extract the old valve stem seal using a specialized puller or needle-nose pliers; clean the valve guide seat.
Installing New Seal:
Lightly lubricate the new seal’s inner lip with engine oil, then press it in vertically using an installation sleeve (e.g., BMW tool #113450) to avoid misalignment.
Reassembly:
Reinstall valve springs and locks, then torque camshaft bolts to spec (e.g., N52 engine: 20Nm + 90° turn).
Important Notes:
Do not hammer or force the seal, as it may deform the lip.
After installation, check valve clearance (some BMW models require hydraulic lifter adjustment).
4.Compatible Models
Engine Series | Displacement | Example Models | Chassis Codes | Notes |
N52 | 2.5L / 3.0L | 325i, 328i, 525i, 530i | E90, E60, E83 | Naturally aspirated I6 |
N54 | 3.0L Twin-Turbo | 335i, 535i, X6 35i | E90, E60, E71 | Early turbocharged I6 |
N55 | 3.0L Turbo | 335i, 535i, X5 xDrive35i | F30, F10, F15 | Updated single-turbo I6 |
B48 | 2.0L Turbo | 330i, 530i, X3 30i | G20, G30, G01 | Requires valve stem check |
B58 | 3.0L Turbo | 340i, 540i, X5 xDrive40i | G20, G30, G05 | High-performance variant |