Mercedes driver Lewis Hamilton suffered an engine failure in Friday’s opening practice session for the Malaysian Grand Prix while his teammate Nico Rosberg set the fastest time.

Hamilton pulled off the track around 30 minutes into the 90-minute session, and radioed back to the pit-wall that “there was a click in the rear, the gears still worked but I stopped the car like you told me to, but I would have made it back.”

His engineer replied “we are a bit worried about this because it’s a race engine.”

Hamilton did not return for the rest of the session as the crew worked on his car.

Rosberg had a time of 1:40.124, a third of a second quicker than Ferrari’s Kimi Raikkonen, who led his teammate Sebastian Vettel.

Australian Daniel Ricciardo in a Red Bull was sixth fastest in 1:41.787.