Likely causes, most common first
Vacuum leak
Idle hunts up and down instead of shaking evenly.
Collapsed engine mount
Engine shake felt in the cabin only at idle and in gear.
Checks to run first
- 1.Scan for misfire counts per cylinder
- 2.Listen for a hiss around the intake
- 3.Watch the engine rock when someone blips the throttle
Frequently asked questions
- engine shakes at idle but smooths out when driving?
- A shake at idle that clears under load is usually a misfire, a vacuum leak or collapsed engine mounts.
- Is it safe to drive with this?
- Short local trips are usually fine, but the fault will get worse and often damages other parts if you leave it.
- How much does it cost to fix?
- The most likely repair is spark plug replacement, which runs $80–$675 in the US including labour, or $25–$180 in parts if you fit it yourself.
Engine & drivetrain parts
Filters, belts, pumps, plugs, clutches and gaskets
Find parts that fit
Year, make, model, trim — then only parts that fit your car.