Oil pressure warning light: What is the problem?

Oil warning light
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The oil pressure indicator warns of a drop in engine oil pressure. This light comes on if the oil pressure in the engine does not reach the required level. If the lubrication system is in order, the oil pressure warning light will come on after turning the key to the second position, informing us that there is no pressure in the engine.

However, after starting the engine, the pressure will increase, and the warning light will go out. Beware that if the oil pressure indicator lights up even after starting, it means that there is a lack of engine oil in the engine or there is a malfunction in the lubrication system.


We will look at these malfunctions in today's article, but first, let's talk about what causes the oil pressure light to come on. What if the symbol does not appear on the dashboard even after turning on the ignition?

Possible problems if the oil pressure warning light does not come on at all

  • Faulty oil pressure sensor

  • Faulty oil pressure warning light

  • Interrupted power supply to the sensor

The oil pressure warning light is connected to the oil pressure sensor, which is located in the pressure line of the engine lubrication system behind the oil pump. If the oil pressure is sufficient, it pushes the engine oil against the diaphragm of the switching contact, which is connected to the vehicle frame.

In this case, the connection to the vehicle frame will be broken, causing the oil pressure warning light to go out. If the pressure is insufficient, the oil pressure warning light will light up, and, in some cars, the engine will go into emergency mode.

As mentioned earlier, the oil pressure warning light coming on is caused by a drop in the engine's lubrication system, which can cause several malfunctions. Let's have a look at them.

Engine oil pressure drop:

  • loose or cracked oil intake pipe

  • there is no or very little oil in the engine

  • oil pressure control valve is opened at low engine speed

  • worn or otherwise damaged oil pump

  • worn crankshaft main bearings

  • clogged strainer for the engine oil supply

  • clogged oil filter

However, one problem mentioned is not necessarily behind the oil pressure warning light. A very common cause of this light coming on can simply be a damaged oil pressure sensor. In this case, everything is fine in the engine, and only inaccurate information from the sensor can cause the oil pressure warning light to signal.

On the other hand, if it is a problem with insufficient engine oil pressure, in such a case, the engine lubrication will be insufficient.

Insufficient engine lubrication can cause:

  • seizure of the main crankshaft bearings

  • seizure of connecting rod bearings

  • seizure of piston rings

  • seizure of the piston in the cylinder

  • seizure of the piston pin

  • seizure of valve lines

  • jamming or damage to the camshaft and cams

Neither of these means a cheap fix, so you should turn off the car immediately after the oil pressure warning light comes on, check the engine oil level, and visit a service center for car diagnostics.