Car Shakes When Accelerating — Causes, Fixes & Cost
When your car shakes during acceleration, it usually indicates a problem with engine combustion, fuel delivery, ignition components, or drivetrain balance. Diagnosing the cause early prevents further damage and improves safety.
Symptoms
- Vibration when pressing the gas pedal
- Shaking between 20–60 km/h
- Jerking or hesitation during acceleration
- Loss of power under load
- Check Engine Light may be on
Most Common Causes
1) Engine misfire
Faulty spark plugs, ignition coils, or injectors cause uneven combustion, leading to shaking when accelerating. See related fault codes such as P0300 – Random Misfire and cylinder-specific misfires like P0301, P0302, and P0303.
2) Bad CV axle or worn joints
A damaged CV axle causes vibration that increases with speed, especially under load.
3) Vacuum leak
Unmetered air entering the intake causes a lean mixture, resulting in hesitation and shaking. Often associated with P0171 – System Too Lean.
4) Dirty or failing MAF sensor
A contaminated MAF sensor sends incorrect airflow data, causing poor acceleration and vibration. This may trigger P0102 – MAF Sensor Low Input.
5) Fuel delivery issues
A weak fuel pump or clogged fuel filter causes the engine to starve for fuel during acceleration.
Can You Drive With This Problem?
Driving is possible but not recommended. Misfires and lean conditions can damage the catalytic converter, while drivetrain issues can worsen quickly. If shaking becomes severe or the Check Engine Light flashes, stop driving immediately.
Severity Level
- Low — Minor hesitation or light vibration
- Medium — Noticeable shaking, reduced power
- High — Strong vibration, flashing Check Engine Light, unsafe to drive
Repair Cost Estimates
| Problem | Typical Cost |
|---|---|
| Spark plugs / ignition coils | €60–€250 |
| CV axle replacement | €150–€350 |
| MAF sensor cleaning / replacement | €10–€180 |
| Fuel pump or filter | €80–€300 |
Possible Fault Codes
- P0300 — Random/Multiple Misfire
- P0301 — Cylinder 1 Misfire
- P0171 — System Too Lean
- P0102 — MAF Sensor Circuit Low Input
How to Diagnose (Step‑by‑Step)
Step 1 — Scan for fault codes
Check misfire counters, fuel trims, MAF readings, and O2 sensor data.
Step 2 — Inspect ignition components
Remove and inspect spark plugs and ignition coils for wear or carbon buildup.
Step 3 — Check CV axles and joints
Look for torn boots, grease leakage, or excessive play in the axle.
Step 4 — Test fuel delivery
Measure fuel pressure and check for clogged filters or weak pumps.
Recommended OBD2 Scanner
To diagnose shaking during acceleration, you need an OBD2 scanner that can read misfire counters, fuel trims, and live sensor data. A good scanner helps pinpoint whether the issue is ignition, fuel, air, or drivetrain related.