Before it starts
- Ask for a genuinely cold engine.
- Match the VIN and registration to the documents.
- Look beneath the car for fresh fluid.
- Check fluid levels only where it is safe.
Signal field notes
Buy with your eyes open. Describe problems clearly.
Practical inspection prompts for everyday vehicles—written to help a driver notice useful clues, not to replace a professional inspection.
Everyday car notes
Start with the exact variant.
These are inspection prompts, not claims that every example develops the same fault. Engine, gearbox, age, maintenance and use all change the picture.
FORD / FIESTA01
Ford Fiesta: establish the exact engine before judging the car
2012–2018 used-car coverageA practical first inspection for common Fiesta derivatives. The service record, cold-start behaviour and exact engine specification should tell one consistent story.
What to check
- Start the engine genuinely cold and watch the warning-light self-test complete.
- Confirm the exact engine and oil specification from the vehicle record and supporting invoices.
- Look for coolant loss, staining, overheating history or unexplained top-ups.
- Check tyre wear, clutch operation, steering and suspension noise on an ordinary road test.
FORD / TRANSIT CUSTOM02
Ford Transit Custom: value the duty cycle, not only the mileage
Early 2.2 TDCi rangeWorking vans need a commercial appraisal. Load use, idle time, body conversion, service evidence and downtime risk can matter as much as the odometer.
What to check
- Identify power output, wheelbase, roof and body conversion before comparing prices.
- Inspect the load area, door operation, floor and tie-down points for duty-cycle evidence.
- Start cold, record smoke, warning lamps, idle quality and any belt-side or driveline noise.
- Check clutch, gearbox, braking, tyres and steering under an appropriate safe test.
MAZDA / 303
Mazda3: match the SKYACTIV engine to the previous use
2014–2015 SKYACTIV rangeThe exact petrol or diesel derivative and its journey history should be established before treating two similar-looking Mazda3s as equivalent.
What to check
- Use the UK model-year derivative list to distinguish petrol and diesel powertrains.
- Check oil level and supporting service invoices against the exact manufacturer requirements.
- Ask whether a diesel mainly covered short or sustained journeys and record any emissions warnings.
- Listen from cold, then test clutch or automatic operation, braking and steering once safe.
VAUXHALL / CORSA04
Vauxhall Corsa E: use a low-speed test to expose ordinary wear
Corsa EA small-car appraisal should verify the exact engine, clutch or automatic behaviour, suspension, tyres and electrical equipment rather than relying on presentation.
What to check
- Watch every warning lamp illuminate and then clear normally.
- Listen for suspension noise over a broken but safe surface.
- Check clutch bite, gear selection and bearing noise from cold.
- Run heating, air conditioning, windows, locks and infotainment.
VOLKSWAGEN / GOLF05
Volkswagen Golf Mk7: engine, gearbox and use are part of the specification
Golf Mk7Identify the exact derivative before applying maintenance advice. Diesel emissions systems, manual clutches and automatic gearboxes do not share one inspection path.
What to check
- Resolve the exact engine, power output and transmission.
- Ask how the car was used and whether emissions or engine warnings appeared.
- Check engine- and gearbox-specific service evidence.
- Listen for driveline vibration or unusual noise during a safe road test.
NISSAN / QASHQAI06
Nissan Qashqai J11: verify the engine and transmission first
Qashqai J11Equipment, engine and transmission combinations vary. A clean-looking Qashqai still needs a cold start, complete electrical check and variant-specific service review.
What to check
- Resolve the engine and gearbox before comparing examples.
- Check transmission behaviour from cold and during parking manoeuvres.
- Test start-stop, cameras, sensors, infotainment and climate control.
- Listen for suspension noise and inspect the entire tyre tread.
Explain the signal
Give a mechanic evidence, not a guess.
A useful description separates what you observed from what you think caused it.
Try the diagnostic concept →- WHEN
Cold, hot, starting, braking, turning, accelerating or at a particular road speed?
- WHERE
Engine bay, one wheel, under the floor, exhaust area or difficult to locate?
- CHANGE
Does the rhythm follow engine speed, road speed, steering angle or pedal input?
- WARNING
Which lamps, smells, smoke, fluid, vibration or change in control appeared with it?
Symptom and warning index
Start with what you can see, hear or feel.
Choose the closest description, then record when it happens and the exact dashboard or scanner wording. These prompts help organise evidence; they do not diagnose a failed part.
Symptoms
12 topicsEngine shaking or vibration
Note whether it happens at idle, under acceleration, while braking, or at road speed.
Start a symptom reviewRough or unstable idle
Say whether the engine is cold or warm and whether the revs rise, dip, or stay uneven.
Start a symptom reviewWhite exhaust smoke
Record when it appears, how long it lasts, and whether the amount changes.
Start a symptom reviewBlue exhaust smoke
Note whether it appears at start-up, during acceleration, or after slowing down.
Start a symptom reviewBlack exhaust smoke
Record when it appears and any change in engine response or warning lights.
Start a symptom reviewVehicle overheating
Include the temperature reading or warning text and the conditions when it changed.
Start a symptom reviewHigher fuel or energy use
Compare like-for-like journeys or fill-to-fill figures and note recent changes in use.
Start a symptom reviewSlow or difficult starting
Describe whether the engine turns slowly, clicks, or turns normally without starting.
Start a symptom reviewVehicle will not start
Say what happens when you try: no response, a click, slow turning, or normal cranking.
Start a symptom reviewEngine stalls
Note whether it happens at idle or while moving, and what warning or message appears.
Start a symptom reviewUneven running or suspected misfire
Include any scanner codes exactly as shown and describe the change in power or vibration.
Start a symptom reviewKnocking or ticking noise
Record when it starts and whether its rhythm changes with engine speed or temperature.
Start a symptom reviewDashboard warnings
11 topicsCheck-engine light
Say whether it is steady or flashing and include any scanner codes exactly as shown.
Open diagnostic intakeABS warning
Copy the dashboard wording and describe any change you noticed in braking behaviour.
Open diagnostic intakeBattery or charging warning
Note when it appeared and any starting or electrical changes that came with it.
Open diagnostic intakeOil-pressure warning
Copy the exact warning text and say when it appeared.
Open diagnostic intakeAirbag or SRS warning
Record the exact message and whether another warning appeared at the same time.
Open diagnostic intakeTyre-pressure warning
Include any displayed pressure readings and recent tyre or wheel work.
Open diagnostic intakeTraction-control warning
Say whether it appeared during wheel slip or on a clear road, and if it stayed on.
Open diagnostic intakeStability-control warning
Copy the display text and note whether steering or handling felt different.
Open diagnostic intakeTransmission warning
Record the message, selected gear, and any change in how the vehicle shifts.
Open diagnostic intakeCoolant-temperature warning
Include the gauge reading or message and what the vehicle was doing when it appeared.
Open diagnostic intakeBrake-system warning
Copy the dashboard wording and describe any change in pedal feel or braking behaviour.
Open diagnostic intakeThese Signal-authored prompts help you describe a symptom or dashboard warning clearly. They are not a diagnosis or a vehicle-reliability ranking.
Open research example
Open the BMW M54 audio lab →A real BMW audio dataset, with its limits left visible.
Try Signal’s on-device comparison against four small reference groups derived from 34 recordings of one BMW M54B25 engine. It is a working research demonstration—not BMW-wide fault coverage.
Exact derivative search
Open the vehicle library →Browse the UK model-year catalogue.
Resolve engine, power and transmission from the source-labelled VCA derivative set before applying guidance.
Vehicle tools
Open the code reference →Look up a code before choosing a repair.
Read the generic meaning, see where vehicle-specific information is needed, and bring the code and symptoms to an inspection.
UK repair costs
Check a garage quote →Understand the quote in front of you.
Break out parts, labour, diagnosis and VAT after the garage has identified the work. A fault code alone is not a repair estimate.
These guides are general starting points. Always use the handbook and manufacturer schedule for the exact registration, engine and gearbox. Stop driving and seek qualified help when there is a safety warning, loss of control, overheating, smoke, a strong fuel smell or serious fluid loss.