Valve Cover

Valve Cover is attached to top of engine (cylinder head). It covers the valves which are soaked in oil. Valve Cover Gasket seals the Valve Cover to prevent oil escaping. Valve Cover Gaskets wear out after a few years and allow oil to escape down side of engine.

Oil Pan

Oil Pan contains the oil used by engine to keep engine parts free to move. Oil Pan is attached to bottom of engine. Oil Pan Gasket is used to stop engine oil from escaping from Oil Pan. Oil Pan Gasket wears out after a few years and allow oil to escape down the side of the Oil Pan. Replace Oil Pan Gasket

Oil Filter

Oil Filter removes any dirt from engine oil as the oil is pumped around the engine. Dirt ends up in oil as engine parts wear and those worn bits get carried off in the oil. Oil Filters not screwed on tightly enough to the engine can cause oil to escape.

Drain Plug

Oil Drain Plug allows oil to be drained out of the Oil Pan. Oil needs to be changed in an engine regularly. Drain Plug can get damaged and worn out. Where the drain plug goes into the Oil Pan can also get damaged. Damaged or dirty Drain Plug will allow oil to escape from the oil pan.

Main Seal / Front Crankshaft Seal

Main Seal stops oil from escaping from the front of the crankshaft as the engine runs. Main Seal is located behind the engine pulley that has a belt or belts running off it.

Rear Seal / Rear Crankshaft Seal

Rear Seal stops oil from escaping from the rear of the crankshaft as the engine runs. Rear Seal is hidden by the transmission as this is where the transmission connects to the engine. If Rear Seal is bad, oil will come out between the Transmission and Engine.

Camshaft Seal

Camshaft Seal prevents oil from getting onto timing belts. Unlike Timing Chains, Timing Belts will be damaged should oil get onto them. Camshaft Seals wear out over time and will cause oil to appear on the Timing Belt side of the engine.

Timing Chain Cover

Timing Chain is covered in oil from engine. Timing Chain Cover is usually on the same side of the engine as the Main Seal. To prevent oil escaping, Timing Chain Covers use a Timing Chain Gasket. When a Timing Chin Gasket fails oil will start to appear outside of the Timing Chain Cover.

Crankcase Breather

Crankcase Breather allows pressure which may build up in the oil pan to escape. When the pressure escapes, it brings oil with it. Over time the Crankcase Breather Tube can fall apart allowing the oil air mixture to escape onto the Valve Cover.

Oil Cap

Oil Cap allows engine oil to be added to an engine. Over time an Oil Cap can wear out or be lost allowing oil to escape from the Valve Cover.

Oil Pressure Sensor

Oil Pressure Sensor tracks the pressure of the oil in the engine. Sometimes the pressure sensor can fail and allow oil to escape through it.

Dipstick

Dipstick measures the amount of oil that is in the engine. If Dipstick is left out, then oil can escape out of the hole it goes into.