Preventive maintenance is also necessary by regularly changing the oil which may be old and may be diluted and contaminated thus causing premature wear to the engine. You will need all the tools needed and lots of rags or newspapers to use in case of spills beforehand. Expect possible problems because the engine and exhaust parts will be hot in the process. Park the car on a flat surface and turn on the engine until it reaches normal operating temperature and then switch off. Take off valve cover filler cap, tie rags around the filter housing to absorb spills, jack the vehicle up on jackstands, and loosen under the vehicle splash cover fasteners. Place a drain pan under the drain plug and take out the plug and ensure it drains gradually checking it to see whether it has metal shavings. Wipe the drain plug and the surrounding area around the drain plug before replacing the drain plug with another one and tightening it. Find and clean the oil filter housing, remove the dust cap of the valve and press the valve in order to empty the filter housing of oil. Unscrew the oil filter housing, wipe it and use a new O-ring and lubricate it using clean engine oil and fit the new filter element. Install the filter housing with screws on the engine and tighten the dust valve cap on the engine should it have one. On certain types of engines, it is necessary to loosen the oil filter with a wrench, remove the old one wiping the mount surface, matching the old with the new one, lubricating the gasket on the new IAT filter and fitting it as the instruction of the manufacturing company. Once all tools and rags have been removed, make a fresh addition of oil by use of the oil filler cap, ensure the level is maintained and then start the engine so that the oil is circulated. Keep the engine running few minutes and monitor the oil level once again and pour more oil as required. Look after leakages and correct oil level in the initial few journeys following the change. Disposal of the old oil should be done in a responsible manner where the oil is recycled. Once the oil has been changed reset the service indicator with either the windshield wiper switch of the instrument cluster buttons in order to keep a proper record of the engine operating time and the vehicle mileage.