Porsche-specific VarioCam code (Porsche fault 174). The measured intake camshaft position on bank 1 (cylinders 1-3) deviates from what the DME commanded, or the adjustment cannot be completed. On the M96/M97 flat-six this is the classic VarioCam wear code: worn actuator chain-guide pads, stretched cam/intermediate chains, a sticking oil-control solenoid, or low/dirty oil. Replacing VarioCam wear pads, chains, actuators and solenoids is considered normal maintenance around 60-80k miles on these engines.
SYMPTOMS
- Check-engine light
- Rough idle
- Slight power loss
- Rattle on cold start (worn chains/actuator)
- Often runs otherwise normally
LIKELY CAUSES
- Worn VarioCam actuator wear pads / chain guides
- Stretched timing or cam chains
- Sticking or clogged camshaft oil-control solenoid (dirt in hydraulic valve)
- Low oil level or degraded/wrong-grade oil
- Solenoid wiring/connector fault
DIAGNOSIS STEPS
- Read live camshaft deviation on bank 1 with a Porsche-capable tool (flag deviation beyond spec, roughly +/-6 degrees)
- Check oil level and condition; confirm correct A40 / 0W-40 grade
- Remove, inspect and clean the oil-control solenoid and its screen
- If deviation persists, inspect VarioCam actuator, chains and wear pads (borescope or engine-out)
- Replace wear pads/actuator/chains as a set if worn
RELATED PARTS
- VarioCam actuator / wear pads
- Camshaft oil-control solenoid
- Timing / cam chains