What Is Oil Pressure?

Jun 2, 2020

What Is Oil Pressure?

Oil is essential to keeping a car running smoothly and running a car without oil (even for a short period of time), will cause the engine to melt and/or explode. But it isn’t just as simple as adding the oil and off you go. Engine oil needs to be pressurised and that’s what gives the car’s engine oil pressure.

The oil works under that pressure to make its way between the various contact surfaces of the moving parts of the engine, creating a layer of lubricating oil. This will make the engine last many years, as less friction means less heat and less chance of the engine melting and/or exploding!

How is oil pressure created?

Oil pressure is created when the oil is pushed through the engine by the oil pump, forcing it to move faster and therefore pressurising it. Your engine can lose oil pressure when there is wear inside the engine that creates too much of a gap between the metal parts for the oil to fill or when the pump becomes slack.

What causes low oil pressure?

If your oil pressure light comes on and you decide to ignore it, it could lead to serious damage and high repair costs. The light could come on for the following reasons:

Low oil level

When the level of oil in your car is low, the oil pump can draw up air from the sump causing the oil to turn into a foam. Foaming can lead to excessive oxidation, reducing the lubricating properties of the oil. With low oil levels, the pump will not be able to generate enough pressure.

Oil filter obstruction

After the oil leaves the pump, it passes through the filter which prevents debris and contaminants from passing through the engine. The filter creates a resistance in the oil flow but is not disruptive. As debris in the oil is built up, the restriction of oil flow increases which can result in a completely blocked oil filter.

Worn engine bearings

Oil is pressurised by the resistance that flow produces. The resistance is accumulated by the openings in the engine through which the oil flows and through the amount of clearance there is between the bearings and crankshafts. These bearings will wear down, causing the amount of clearance to increase and therefore decreasing the pressure.

Dirty oil pump

The oil pump will take the oil lying at the bottom of the oil pan and circulates it under pressure to the bearings, piston and camshaft of the engine. If there is dirt in the oil, the filter will prevent it going into the oil pump, filling the filter with debris. There could also be clearances in the oil pump, reducing the ability to pump efficiently, reducing the flow and pressure.

Is your oil pressure light flashing on your dashboard? If so, we can help you find a mechanic to sort this problem. Get your quote with www.mycarneedsa.com/get-a-quote/

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