Your car’s engine is a mechanical and technological work of art. However, without oil to lubricate its moving parts, it can’t function. Oil pressure circulates the oil through the engine, keeping it running smoothly and at the optimum temperature. That’s why recognizing and preventing low oil pressure symptoms as soon as they appear is vital.
What is oil pressure?
Oil pressure is the force that oil exerts on a solid surface. An oil pump must pressurise oil to circulate between the moving parts of an engine. The oil forms a barrier, allowing parts to move freely across contact surfaces. The basic principle behind any oil pump is straightforward, using one or more gears to generate an appropriate amount of pressure needed by the motor at all times.
Low oil pressure symptoms
Keep an eye on your oil pressure gauge. If you don’t have an oil pressure gauge, a warning light will turn on when there’s a problem. If this happens, you should stop your vehicle as soon as it’s safely possible. Signs of low oil pressure include:
- Oil pressure light comes on
The engine might be using too much oil, or there’s not enough oil to lubricate it. The light may be on because of a faulty sensor or warning light or a defective oil pump. Most likely, however, the light is on because of low oil pressure.
- Engine temperature rises
The oil’s decreased ability to reduce friction also leads to increased heat, prompting overheating. Engine overheating may also indicate a head gasket leaking oil into the coolant, reducing the heat transfer through the cooling system.
- The engine runs rough and is slow to accelerate
Low oil pressure decreases the oil’s ability to reduce friction and provide proper lubrication, causing the engine to work harder and resulting in premature wear and failure.
- Blue smoke from exhaust and burning oil smell
Blue smoke often indicates the engine overheated, and oil is in the combustion chamber or leaking onto hot metal surfaces.
- Loud knocking noises from the engine
When your engine oil is running low, your engine’s components stop receiving the lubrication they need to function correctly. Once this happens, you may start to hear clunking, knocking, ticking, or grinding noises coming from your vehicle’s engine.
What causes low oil pressure?
Low oil pressure can be caused by several factors. It could be a mechanical issue or a problem with the oil. If your car has low oil pressure, a mechanic will look for the following causes:
Low oil levels
When there isn’t enough oil to circulate correctly, pressure drops. Check oil levels between oil changes to ensure your car isn’t running with less engine oil than it needs.
Incorrect oil viscosity
If your engine requires 5W viscosity and you replace it with 20W oil, your oil pressure may drop. A low viscosity oil reduces resistance, triggering a low-pressure indicator. Conversely, higher viscosity oil slows down flow, resulting in improper lubrication.
A dirty oil filter
Most manufacturers require a filter change when changing the oil. The oil filter is responsible for trapping debris that will harm your engine parts. If the filter becomes clogged, it can stop oil flow, reducing pressure. Most oil filters include a relief valve to let oil bypass the filter if it is clogged. Although the bypass allows engine oil to circulate as a last resort, it also allows contaminants into your engine.
Faulty oil pump
If the oil pressure is still low after using correct oil viscosity and a clean filter and your levels are acceptable too, you may have a faulty oil pump. Diagnosing a faulty oil pump is a challenge because it may sit inside the oil pan or another hard-to-access location. A mechanic will need to check it.
Internal oil leak
In some instances, a head gasket failure near an oil passage will leak oil into the piston combustion chamber or onto the engine.
What to do if you have low oil pressure
Having low or no oil can destroy your engine, so get the problem fixed as soon as possible. Check what other issues may be causing a low oil pressure warning. Getting a diagnosis from a mechanic is especially important if you notice low oil pressure symptoms and no warning lights are on. Additional issues may need to be fixed, such as a faulty oil pump, damaged engine seals or more.
If the low oil pressure light on your dash comes on, you must stop driving immediately. Let the engine cool and check the oil level. If it’s low, adding oil may be enough to return the pressure to normal, at least temporarily. If it persists, have the issue checked by a technician. Driving with little or no oil will result in severe and expensive long-term damage.
Nelson Xavier Ssenyange
Germax Auto Spares & Garage
Lukade Road, Naalya