Ferrari's Carlos Sainz set the fastest time across the day, but only after team-mate Charles Leclerc dislodged a drain cover which took time to fix.
The loss of running, though, allowed for even more time to spy on the new 2024 cars in the pitlane and garages.
INSIGHT: What we learned on day two of 2024 F1 testing in Bahrain
Source: Autosport