To check a lorry’s oil level with the dipstick, its manufacturer specifies checking before starting, with a cold engine and the vehicle on level ground. What should you do?

Correct answer

Check the level with the engine cold and stopped, before starting.

Check with the engine cold and stopped and the vehicle on level ground, following this vehicle’s instructions. The level must be between the minimum and maximum marks. Manufacturers do not all specify the same temperature or waiting period: some allow checking after warming up and waiting with the engine stopped. Therefore a warm-engine check is not inherently wrong. Changing the oil is a separate operation and must follow the manufacturer’s procedure, including precautions against hot oil.