Proton Persona Carbon — Port Injection, No Issue
Proton Persona · 2016–present
Persona 1.6L CAMPRO is port injection — fuel washes the intake valves on every cycle. Carbon buildup on intake valves is NOT a concern. Standard throttle body cleaning every 40,000 km is sufficient.
Carbon Buildup — Proton Engines Malaysia
The X50/X70/X90 1.5T TGDI uses direct injection — more prone to intake valve carbon buildup than port-injected engines. Short city trips without occasional highway runs accelerate buildup. Every 3–6 months, take a 30-minute highway run at 3,000+ rpm to burn off deposits. An intake cleaning service (RM 200–400) every 50,000–80,000 km is worth considering. Saga/Persona with port injection have much less carbon risk — only standard service needed.