A high-pitched whine indicates an airflow restriction or a motor bearing issue. Check for a clog first.
- Unplug the vacuum.
- Remove the dust cup and empty it. Inspect the inlet where the cup attaches for debris.
- Detach the hose from the pod and the wand. Look through the entire length for obstructions.
- Remove the floor nozzle and check the opening and the brushroll chamber for blockages.
If that didn't work, and the noise persists with all attachments removed and filters clean, the motor bearings may be failing. Contact Shark customer service for support. Do not continue to run it with that noise.