Engine fault symptoms: start with what you notice
Choose the description that fits what has changed. Note what you saw or heard without trying to make the fault happen again. The same symptom can have different causes on different cars.
The engine is behaving differently
- It won’t start. Tell us whether it turns over, clicks or does nothing.
- It has lost power. Note whether it struggles on hills, during acceleration or on level ground.
- It makes a new noise. Say whether it happens at a cold start, at idle or under load.
- You suspect a timing fault. Mention a sudden stop or any findings from another garage.
Temperature, fluids or exhaust changes
- The engine is overheating. Check what to do before going any further.
- It is using oil. Note how much you added and the distance covered.
- There is exhaust smoke. When it appears and how long it lasts matter alongside colour.
- You see oil in the coolant. A photo can show the appearance, but does not identify the source.
- A test found low compression. Share all the cylinder readings if you have them.
If a critical warning appears while driving
For an overheating or low oil pressure warning, stop as soon as it is safe, switch off and follow the owner’s manual. When it is safe to do so, ask about engine diagnostics.
See all options
Engine using more oil than usual?
Topping up more often than usual? Find out what to note and how a workshop distinguishes an external oil leak from oil being burnt.
What to do when your engine overheats
If your engine overheats, stop safely. Find out what details help us investigate the temperature warning and whether the engine was damaged.
A new rattle, tap or knock from the engine
Heard a new rattle, tap or knock? Find out what helps a garage trace the source and when to stop the engine and ask for advice.
When the engine won’t start
Does the engine turn over, just click or do nothing? Find what to tell the workshop and how to discuss getting the car there.
Your car is losing power
Find out what to tell the workshop if your car loses power under load, on hills or when warm. The cause may be inside or outside the engine.
Smoke from the exhaust
Smoke from your exhaust? Tell us its colour, how long it lasted and when it appeared. Those details help choose the next checks.
A low compression reading in one or more cylinders
Had a low compression reading? Find out what the test can show, what else may need checking and which results to share with the workshop.
Oil in the coolant
Noticed an oily film in the coolant tank? See what the workshop can check and why the appearance alone does not identify the source.
Signs of a possible engine timing fault
A start-up rattle, timing fault code or sudden stop can have different causes. Find out what to tell the garage and what needs confirming.