Oil leak
Last reviewed 22 October 2026. General information, not advice about a particular car.
Keep an eye on it Normal wear or minor. Check it at the next service.
The engine or gearbox is weeping oil. "Not excessive" means it is not dripping onto the road, which would be a fail. Common culprits are gaskets and seals. Keep the oil level topped up and ask a garage where it is coming from.
What the wording on the certificate means
You’ll usually see something like “Oil leak, but not excessive”, often with a position such as “nearside front” (the passenger side) and a reference to the MOT inspection manual in brackets.
Oil is seeping from the engine or gearbox, but not enough to be a danger. Common sources are the rocker or cam cover gasket, the sump gasket and the oil filter seal.
Why it matters
A small leak is often slow and cheap to fix, but oil dripping onto the exhaust can smoke or catch fire, and a car that runs low on oil can damage its engine.
What to do
- Check the oil level on the dipstick every couple of weeks and top up as needed.
- Look for drips where the car is parked. A piece of cardboard underneath overnight shows how fast it’s leaking.
- Ask the garage where it’s coming from: a cover gasket is a much smaller job than a crankshaft seal.
Will it fail the next MOT?
An advisory isn’t a fail, and the car can be driven, as long as it stays roadworthy. An excessive leak, or one likely to harm the environment or create a risk to safety, is a major fail.
If you’re buying a car with this advisory
A small seep is normal on many older engines. A freshly steam-cleaned engine bay can hide a leak, so look for oil on the underside too. If the same advisory shows up at test after test, it has probably been left unrepaired.
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