Red oil can on the dash? Get off the road and switch off
Stop at the first safe spot, not the next servo or the end of the trip, and turn the engine off. Every extra minute of running on low pressure risks the bearings inside it. On a busy road, put the hazards on and wait well clear of the traffic, behind a barrier if there is one. Call roadside assistance if you have it. If anyone is hurt or in danger, call 000.
Is it the oil pressure light or the oil level light?
| Red oil pressure light | Amber oil level light | |
|---|---|---|
| What it's telling you | Oil isn't being pushed around the engine hard enough, right now | The level has dropped and it's time for a top-up |
| What to do | Stop safely and switch off | Top up soon with the oil your manual lists |
| Can the car be driven? | No, not until you know the cause | Usually yes, until the top-up's done, according to the UK's AA |
Not every car has both, and symbols vary, so check the manual. If it's red, treat it as pressure: the AA warns that driving on with it lit can cause catastrophic engine damage.
Why does oil pressure drop?
RACV lists the usual causes: low oil level, an oil leak, a faulty oil pump or a blocked oil filter. The level is the one thing on that list you can check from the roadside, which is why the dipstick comes next.
Sometimes the fault is the sender, the small sensor that reads the pressure, and the engine is fine. You can't tell that from the driver's seat. Treat the light as real until a mechanic has measured the pressure with a gauge.
What to do once you've stopped
Let it cool first
RACV says to check the level only after the engine has cooled. Give it at least 10 minutes, on flat ground, so the oil drains back into the sump (the tank at the bottom of the engine).
Read the dipstick
Pull it out, wipe it, push it fully back in, then pull it out and read it. Some newer cars have no dipstick and show the level on a screen instead, and the manual shows how. If there's no oil on the stick at all, RAA's advice is plain: don't drive the car.
If it's low, top up with the right oil
Use the grade in the owner's manual. Volkswagen's UK advice for its own cars is to top up, start the engine, watch the light for five seconds, then switch off. If the light's still on at that point, the next call is roadside assistance.
If the level's fine, don't restart
That means there's oil in the engine but it may not be moving. Volkswagen says to call roadside assistance here. CAA-Quebec, the Canadian motoring club, says a light that stays on after a restart means switch off right away and have the car towed.
Send us what you found
Tell us the car and your postcode in the card, and put what the dipstick showed in the note. If the car can't move, say so. The mechanic will tell you whether a tow or a mobile visit makes more sense.
Leave the key alone if
- The dipstick shows no oil.
- The level is fine but the light was on, or it stayed on after a top-up.
- You heard knocking or ticking from the engine as the light came on.
- There's a fresh trail of oil under the car, or oil is leaking quickly.
- You can smell burning oil, or there's smoke from under the bonnet.
What will the mechanic test?
A good mechanic starts with the level, the state of the oil and any sign of a leak. Then they take out the sender, screw in a mechanical gauge and measure the real pressure. That one test separates a faulty sensor from a genuine pressure problem, and it's worth asking for before anyone replaces parts.
If the pressure really is low, the next suspects are the filter, the pump and its pick-up (the strainer tube that draws oil from the sump), then engine wear. A mechanic who does engine repairs suits this better than a quick-service bay. Before anything gets dismantled, ask for a written estimate, as Consumer Affairs Victoria advises for any repair.
If the oil was simply low, the job isn't finished. It went somewhere, so ask where: a leak, or an engine that's burning it.
What's yours to do, and what's the mechanic's
You can
- Stop, switch off and stay clear of the traffic.
- Check the oil once the engine has cooled, on flat ground.
- Top up with the grade in the manual if it's low.
- Note when the light came on, and whether you heard anything from the engine.
Leave to the mechanic
- Measuring the oil pressure with a gauge.
- Testing or replacing the sender, filter or pump.
- Finding out where the oil went.
- Checking for engine damage if the car ran on with the light lit.
What we'd do
We'd treat the red oil can as a stop sign every time. Switch off, let it cool, read the dipstick. If the oil was low and a top-up puts the light out, we'd drive gently to a mechanic that same day and ask where the oil went. If the level's fine or the light stays on, we wouldn't turn the key again. We'd ask for a mobile mechanic or a tow. It's a small hassle next to an engine.