Warning lights
Oil warning light on: what it means and what to do
The red oil warning light (an oil can) warns that engine oil pressure is too low. Without pressure the internal parts run dry and the engine can seize within minutes: stop as soon as it is safe and switch off the engine.
Stop as soon as it is safeWarning lights
Reviewed by Daniel Morales, founder of Reprorace SL, on
Is it serious? Can I keep driving?
Do not keep driving. Do not carry on even if the engine seems fine: few faults destroy an engine faster. Check the level with the engine off and, if the light stays on after topping up or the level was correct, do not restart: call a tow truck.
A careful, general answer: only someone who inspects the car can say whether it is safe to drive. When in doubt, stop somewhere safe and call for assistance.
Most likely causes
- Low oil level: through consumption or a leak. This is the first thing to rule out.
- Pressure sensor or switch: a faulty sensor or connector can give a false warning, but only measuring the real pressure confirms it.
- Oil pump or pick-up strainer: a worn pump or a strainer blocked by sludge cannot move the oil the engine needs.
- Wrong or worn-out oil: a viscosity other than the specified one, or oil overdue for a change, lowers the pressure when hot.
- Internal wear: worn bearings let pressure escape; it often shows at idle with the engine hot.
Listed from more to less common in general; on your car they may be different. A fault-code reading and a check at the garage confirm which one it is.
To understand it better: What does a yellow warning light mean compared with a red one? Can I diagnose my car myself? What is live data and what is it for?
Car system: Engine and lubrication
What you can check yourself
Park on level ground, switch off the engine and wait a few minutes for the oil to drain back to the sump.
Check the dipstick: the level should sit between the minimum and maximum marks.
If it is low, top up with the oil specified in the handbook, a little at a time and never above the maximum.
Look for oil stains under the car or oil on the engine that would point to a leak.
Safe checks only: with the engine off and cold whenever you look under the hood, without taking anything apart and without touching hot or moving parts.
Related fault codes
- P0520Engine oil pressure sensor/switch A, circuit: malfunction
- P0521Engine oil pressure sensor/switch A: range/performance
- P0522Engine oil pressure sensor/switch A: signal low
- P0523Engine oil pressure sensor/switch A: signal high
Generic codes that often come with this symptom. Seeing one does not confirm the cause: it is where the diagnosis starts.
How the ECO-LITE helps diagnose it
Plugged into the OBD socket, the ECO-LITE reads the fault codes of the control units that answer, with the freeze-frame data captured when the fault happened, and shows live data on your phone or computer. With your permission, your garage can see them remotely before you bring the car in.
What to look at here: oil pressure or oil switch status and oil temperature, depending on what each car reports; coolant temperature and engine speed.
Frequently asked questions
What is the difference between the red and the yellow oil light?
On many cars red means no pressure (stop now) and yellow means low level or a sensor fault (top up and have it checked soon). Check your handbook: each manufacturer uses them differently.
The light only flickers at idle with a hot engine. Is that serious?
Yes, it needs checking: it may be a marginal level, the wrong oil, the sensor or internal wear. Check the level and do not let it go.
I topped up and the light went out. Can I carry on?
If it goes out at once and stays off, you can drive gently to the garage to find out why oil was missing. If it comes back, stop again.
Does it store a fault code?
Sometimes: P0520 to P0523 monitor the pressure sensor circuit. A real loss of pressure does not always store a code, so the light comes first.
Keep reading
- Engine and lubrication: how they work and what fails
- Car using oil: when it is normal and what to do
- Knocking or pinking from the engine: what it means and what to do
- Blue smoke from the exhaust: the engine is burning oil
- Car symptoms: what they mean and what to do
- Check engine light on: what to do
- How to read and clear your car's fault codes
- OBD fault codes: what each one means