Engine oil should be changed at regular intervals as it keeps the parts lubricated
Inspect for leaks so that you can learn about any problem in the engine before it is too late
Avoid driving on reserve fuel as that can pump the residual junk from the fuel tank
Make sure the air filter is clean and in good condition as it helps in engine's breathing
Ensure there's enough coolant in dedicated reservoir as it helps in heat dissipation
Inspect and change belts if required as they are crucial for smooth functioning of engine
Never ignore the engine light warning on instrument cluster
Try to listen if the engine is making any unusual sound
It's good to get the engine checked by a professional once in a while