Mercedes is changing the engine in Valtteri Bottas’ car following a hydraulic failure during third practice at the Mexican Grand Prix.
Bottas suffered the failure with 10 minutes remaining in the final practice session and stopped in the Foro Sol section at the Autodromo Hermanos Rodriguez.
Mercedes confirmed that his W09 had suffered a hydraulic failure and is swapping PU3 for the PU4 engine that he ran in Austin.
As the engine was already part of Bottas’ pool he will not face a grid penalty, unless any fresh components are required.
The 18-minute Q1 session is scheduled to begin at 13:00 local time, giving Mercedes a short time in which to prepare Bottas' car.