Oil should be changed at the manufacturer’s recommended mileage intervals, but if necessary at certain time intervals instead. Make sure that a new oil-filter element is fitted every second oil change; a filter cannot be cleaned.
To change your BMW engine oil, first ensure that the vehicle is on level ground. It is not advisable to raise the front end on a ramp, for the oil sump is designed to drain when the car is level. If it is tipped, some – but not all – of the oil will come out.
A handy container to collect the oil, so that it does not run over the garage floor, is a 5 litre oil can, laid on its side with its top screwed on and a hole cut in the top side. This will go under most engine sumps and will hold all the oil drained off – from all but the biggest BMW models.
When removing the drain plug from the sump, always use the correct-sized spanner, preferably a socket or ring. If the plug is damaged by a wrong sized spanner, it can be extremely difficult to remove. On some plugs, there is a magnet fitted to attract small particles of metal in the engine oil. These magnets are brittle and can easily be broken by rough handling.
Before draining, run the engine to normal temperature so that the oil thins a little and comes out more easily.
When an oil filter is being removed, oil will overflow as the oil seal is broken. This is a dirty job, and the home BMW mechanic is advised to have his sleeves rolled up.
Tap the BMW filter to break the seal before the retaining screw is completely released. As the filter is spring loaded, it may come off without warning unless the seal is broken first. Several rubber seals are often supplied with the replacement filter element. Compare with the one removed and ensure that a new seal with the correct size is fitted into the groove of the BMW filter housing. The most useful tool for removing the old ring is a hat-pin or dart point.
BMW filters that are screwed completely into the engine may be difficult to remove.
Place a large hose-clip (or a number of them joined together) around the body of the filter and tighten. Hook a loop of wire over the screw of the hose-clip. Place a piece of wood in the other end and lever the wood gently against the side of the filter – so loosening the filter unit. Do not use this method for re-tightening it!