Cylinder Deactivation (Cylinder On Demand)
Cylinder deactivation switches off some cylinders under light load to save fuel, then reactivates them when more power is needed.
What is Cylinder Deactivation (Cylinder On Demand)?
It is used on some V8, V6 and four-cylinder engines. The switch-over is normally barely noticeable, and some cars show the active mode on the display. The deactivated cylinders keep their valves closed so the trapped air acts like a spring.
How it works
Special lifters or rocker mechanisms stop the valves of selected cylinders from opening, and the control unit cuts fuel and spark to them.
Why it matters for your car
Lifter faults on these systems can cause ticking noises or misfire codes. Correct oil level and specification are important because the mechanism is oil-pressure operated.
Other terms
- Agreed Value Insurance
- Alternator Diode (Rectifier)
- Anti-corrosion Warranty (Perforation Warranty)
- Auto Hold (Brake Hold)
- Automatic Climate Control
- Axle Stands (Jack Stands)
- Bar (Pressure Unit)
- Battery Passport (EU)
- Bluetooth Hands-free System
- CHAdeMO Connector
- Clutch Master Cylinder
- DPF Ash Loading
- Engine Displacement (Engine Capacity)
- Fastback
- Fuse Box
- Headlight Restoration
- Misfuelling (Wrong Fuel)
- Steering Wheel
- V Engine (V6, V8, V12)
- VIN (Vehicle Identification Number)