Car shakes at idle
The buyer question: "car shakes at idle"
Book an inspection soon. Stop in a safe place if the shaking is severe, the check engine light flashes, the car stalls, or power drops.
What could cause it
More than one problem can cause the same symptom. These are places to inspect, not a diagnosis.
- An engine misfire or uneven combustion
- Worn or damaged engine mounts
- Air, fuel, ignition, or sensor problems
- A drivetrain or accessory vibration that is most noticeable at low speed
Safe things to check
Keep clear of moving parts, hot components, and traffic. Use the owner's manual for vehicle-specific instructions.
- Note whether the shaking changes in Park, Neutral, or Drive, without putting yourself near moving parts
- Look for warning lights, fluid spots, or a change in idle speed
- Check the owner's manual for the correct response to any flashing warning light
Stop and arrange help if the engine is shaking violently, the check engine light is flashing, the car is stalling, or you smell fuel or burning material. A symptom page cannot tell you that continued driving is safe.
What a mechanic may check
A mechanic may check scan data, ignition and fuel operation, air leaks, engine mounts, accessory drive parts, and whether the symptom changes under load.
If you are considering this car
If this happens on a test drive, ask when it started, whether the seller had it diagnosed, and whether any warning lights were recently cleared. A cold start and a warm idle may behave differently.
Questions for the seller
- When did the shaking start, and does it happen cold, warm, or both?
- Has a shop diagnosed or repaired it? Can I see the written work order?
- Are any warning lights on or recently cleared?