Symptoms
- Noticeable jolt or shudder when the gas engine kicks in or shuts off
- Vibration felt through the seat or steering wheel during the switch
- Problem happens consistently at certain speeds
- Transition used to feel smoother
Likely causes
- CommonNormal characteristic of some hybrid systemsSome hybrid designs have a slightly noticeable transition by design, especially older models or certain architectures.
- PossibleWorn engine or motor mountsMounts that have worn out can allow more vibration to transfer to the cabin during power source changes.
- PossibleFuel system or spark issue causing a rough engine startA engine that doesn't start smoothly will make any transition feel harsher, similar to a rough start in any gas car.
- Less commonSoftware or hybrid control module issueA fault in the system managing the handoff between electric and gas power can cause an abrupt rather than smooth transition.
What to do
- Note if the roughness has always been present (possibly a normal trait for your model) or is a recent change.
- Pay attention to whether the shudder happens at a specific speed or driving condition consistently.
- Check for other symptoms like rough idling or hesitation that might point to a general engine issue rather than something hybrid-specific.
- Compare notes with an owners' community or forum for your specific hybrid model, since some are known for a certain feel.
- Have engine mounts inspected if the vibration feels more like a general shake than a power-source-specific jolt.
- If the transition has clearly worsened recently, have the hybrid system scanned for fault codes.
Tools and parts
Engine or motor mountSearch: “engine mount for your hybrid make, model, and year”
When to call a pro
If the transition feels newly rough or is accompanied by other symptoms, have a dealer or hybrid-certified shop check the engine mounts and hybrid control system.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.