Engine and gearbox (P)
P0021: Camshaft Timing Over-Advanced Bank 2
The intake camshaft on bank 2 is more advanced than it should be. This can be due to a stuck oil control valve or issues with the variable valve timing system.
Checked by a licensed car technician · last reviewed 29 September 2026
Symptoms
- Rough idling
- Decreased fuel efficiency
- Check engine light on
- Reduced engine performance
Common causes
- Oil control valve stuck open
- Sludge in VVT passages
- Low oil pressure
- Faulty camshaft position sensor
- Timing chain or belt issues
How to check it yourself
- Check engine oil level and quality
- Inspect oil control valve for proper operation
- Examine VVT passages for sludge
- Test camshaft position sensor
- Inspect timing chain or belt for wear
Can I keep driving?
The car can be driven, but performance may be reduced. Address the issue soon to avoid further damage.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer