How do you know if an Opel Vectra engine is good?

To determine if an Opel Vectra engine is in good condition, check for any unusual noises during operation, as well as smooth idling and acceleration. Inspect for oil leaks and examine the engine oil’s color and consistency; it should be clean and not overly dark or gritty. Additionally, review the vehicle's service history for regular maintenance and consider conducting a compression test to assess the engine's internal health. A diagnostic scan can also reveal any stored error codes that may indicate underlying issues.