Finding oil spots under a parked vehicle can be both worrying and stressful for any vehicle owner. If the seal’s leak is small, oil may start to accumulate on the underside of the engine. But as the leak gets bigger, the oil leak will become visible in the front side of the engine.  

■Dispersants: This is your oil’s magic ingredient. It gives your oil the ability to absorb and hold solid contaminants so that they don’t damage the engine.

The cover is fixed by nuts or bolts on top, or by screws round the edge. Loosen them all and remove them with their washers. If there are several oil-sealing washers under each fixing, note their order.