BMW 8 Series G15 840i B58 Carbon Intake Valve Build-Up
BMW
2018
B58 3.0 Turbo
⚡ Quick Summary
Severity Level
Low
Safe to Drive?
✅ Safe to Drive
Safety Impact
No direct safety impact reported by owners
Urgency Level
🟢 Low Priority
The B58 direct injection in 8 Series G15 840i accumulates carbon on intake valves above 80,000 miles. Walnut blasting costs £350-600.
Repair / Solution
No confirmed fixes yet. Share yours below.
⚠️ Wrong Diagnosis?
No commonly reported misdiagnoses for this fault yet. If you have replaced a part that did not fix this BMW 2018 problem, submit a wrong diagnosis report — it helps other drivers avoid the same costly mistake.
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