18/07/2026
🔧 BMW 420i (B48) – Check Engine Light at 100,000 km 🔧
This BMW 420i came to us with the check engine light. The engine ran perfectly smooth.
We found the metal mesh inside the VANOS central valve had become loose and damaged, which can lead to VANOS faults.
To ensure a reliable long-term repair, we replaced all related components rather than just the failed valve.
The following parts were replaced:
✅ Exhaust camshaft adjuster
✅ VANOS central valve
✅ VANOS actuator
✅ Timing chain tensioner
✅ Rocker cover gasket
✅ Injector seals
All work was completed following BMW factory spec:
✔️ Engine timing locked
✔️ VANOS adaptations reset
✔️ Vehicle programmed to the latesr I-Step
✔️ Road tested
✔️ Final ISTA diagnostics confirmed no fault codes present
Sometimes the engine can run perfectly while still storing a VANOS fault.
📍 BIMMERWISE – BMW Specialists
Diagnostics | Repairs | Coding | Programming | Hybrid & EV Specialists