Symptoms
- Audible click when the gas engine starts or stops
- Click also heard when starting or turning off the car
- Sound is brief and consistent each time
- No other symptoms like warning lights or rough running
Likely causes
- CommonNormal relay or contactor operationHybrid systems use electrical relays and contactors to connect and disconnect high-voltage circuits, which naturally produce an audible click.
- PossibleNormal engine mount or component settlingMinor clicks can come from components shifting slightly as the engine starts or stops.
- PossibleWorn contactor or relayOver many years and cycles, these components can wear and produce a louder or different-sounding click.
- Less commonLoose heat shield or trim near the engineA separate rattling or clicking source unrelated to the hybrid system itself, like a loose heat shield, can be mistaken for it.
What to do
- Note whether the click has always been present since you've owned the car, which often indicates normal operation.
- Listen for whether the click is a single sharp sound (often normal) versus a repeated rattling or grinding (which is not).
- Check underneath the car for a loose heat shield or trim piece that could be an unrelated rattling source.
- Compare notes with an owners' community or forum for your specific hybrid model.
- Watch for accompanying symptoms like warning lights, rough running, or reduced power, which would suggest a real issue.
- If the sound has recently gotten louder or more frequent, have it checked rather than assuming it's normal.
When to call a pro
If the click is new, louder, or paired with other symptoms, have a dealer or hybrid-certified shop inspect the high-voltage contactors and relays.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.