| Clue | Source | Date |
|---|---|---|
| Archimedes' screw, eg (5,4) | ||
| Part of a car's cooling system (5,4) | Puzzler | 04 Apr 2024 |
| Cooling system component | USA Today | 29 Dec 2017 |
| Cooling system component | ||
| Heart of a cooling system | Wall Street Journal | 24 Apr 2015 |
| Heart of a cooling system | ||
| Part of a cooling system |