First, let's go over the basic parts of the engine oil system, oil, oil filter, oil pump and the oil pump pick-up tube. Most of the motors in cars today require either 5w30 or 10w40 engine oil. The oil filter is the most important part of the oiling system. If the filter fails or is clogged with dirt particles, it will no longer be able to filter the oil. This will cause excessive wear to the engine bearings and crankshaft.
Clean oil is vital to the proper operation of the oil pump.
Dirt particles can also wear the oil pump gears. These gears are so finely machined that a human hair can cause them to break. The most overlooked part of the engine oiling system is the oil pump pick-up screen. This sits near the bottom of the oil pan and can become restricted with contaminates and starve the oil pump. Now let's look at some of the things that can cause your engines oil pressure to decrease.