How to Describe a Car Fault to a Garage So It Is Diagnosed Faster

Say when it happens, not just what happens

Timing is the single most useful clue. Does the problem occur on first starting, after the car has been running a while, when braking, when accelerating or only while turning? Does it come and go, or is it constant?

Intermittent faults are the hardest to track down. If something happens only on some days or in some conditions, say so plainly. That tells the technician what circumstances to recreate.

Try to avoid guessing the cause when you describe it. Saying 'I think it's the gearbox' can steer everyone down the wrong road. Describe what you see, hear and feel, and let the diagnosis work out why.

• On start-up, while driving or when stationary
• When braking, accelerating or coasting
• Turning left, right or going over bumps
• All the time or only occasionally

Cold or hot, fast or slow

Temperature changes how a car behaves. Some faults appear only when the engine is cold, such as a rough idle or a squeal from a belt, and then go away. Others show up once everything has warmed through, like overheating or a clutch that begins to slip.

Speed matters too. A vibration that begins at a certain speed and fades beyond it suggests something different from one that gets steadily worse. A shudder at motorway speed might point towards wheel balance or tracking, while one under braking points elsewhere.

Describe the noise, smell or feel

Try to put the sound into a few words: a rhythmic click, a grinding, a squeal, a rattle, a clunk over bumps, a hum that changes with speed. Say where it seems to come from, front or rear, left or right, and whether it changes when you turn the wheel or press the pedal.

Smells help as well. Burning, sweet, fuel or damp odours each point in different directions. Likewise, mention how the car feels, such as a pull to one side, a vague brake pedal, heavy steering or a loss of power.

Tell them how the symptom changes. Does it get louder with speed, disappear when you press the clutch, or change when you turn the heater or air conditioning on or off? Small details like these narrow the search a great deal.

Warning lights and what changed recently

Note which warning lights are on, whether they are steady or flashing, and when they appeared. Take a photo of the dashboard if you can. Do not clear or ignore a warning without understanding it, and if a brake, oil, temperature or similar light comes on, stop in a safe place and get advice.

Tell the garage about recent changes: new tyres, a recent repair, a long journey, a fill-up of fuel, a bump on a kerb or a stretch of standing water. The cause is often tied to something that happened shortly beforehand.

It is also worth mentioning whether any fault has been looked at before. If another garage already checked something, or a part was replaced to try to cure it, say so. It saves repeating work and tells the technician what has already been ruled out.

A short video is worth a thousand words

If the car makes a sound or shows a symptom you can capture safely, record it on your phone. A passenger can film a noise from the cabin, or you can record the dashboard when the light comes on. Never film while you are driving.

Bring the video, or mention it when you book, so the technician can hear it before the car arrives. At Banks of the Tyne we carry out engine, warning-light and full vehicle diagnostics, and a good description makes that first step quicker. Even so, the exact cause usually needs the car on the ramp and the right equipment.

Frequently asked questions