Symptom log
A sound, smell, feel, light or leak written down the way a technician can use it: what, where, when, how often, since when, and whether it is getting worse. Hand it to the shop with the car.
For a first pass, this sheet is essential only when something seems wrong: one row, written the day you notice it. Otherwise it can wait.
Symptoms
One row per symptom, added the day you notice it and updated each time it happens. Write what you noticed, not what you think the cause is. If a stop-driving line applies, stop first and write later.
How to use this sheet
- One row per symptom. Update the same row each time it happens; start a new row for a different symptom.
- What, where, when, how often. Describe what you noticed in plain words (a squeal, a sweet smell, a pull to the right), where on the car, the conditions (cold, braking, turning, at a speed) and how often (writing it down).
- Observations, not causes. "Grinding from the front left when braking" helps a technician; "bad wheel bearing" is a guess that can send a diagnosis the wrong way.
- Recordings are made by a passenger, or with the car parked. Never by the driver while driving.
- Stop-driving line. Tick it if any line on the stop-driving list applies, and stop before you write.
The example row is Gloria Hernández's fictional check engine light: steady for two weeks, then flashing on the highway with the car shaking. She left the highway and had the car towed, and the outcome column holds the shop's diagnosis. Her son, Luis, kept the log by phone.
The symptom log describes what you noticed. It does not diagnose the car, and no row means a problem is or is not serious: a technician's tests decide that. Any brake, steering, smoke or fuel-smell symptom is a reason to stop and call, not to keep watching.