Mercedes boss Toto Wolff says Lewis Hamilton faced an “imminent” engine failure before engineers undertook a remote fix during the Brazilian Grand Prix.
Hamilton followed up pole position with victory at Interlagos, having profited from Max Verstappen’s collision with the lapped Esteban Ocon to re-claim the lead.
Hamilton’s win, his 10th of the campaign, sealed a fifth straight Constructors’ Championship for Mercedes, but Wolff explained that the race was far from comfortable for the team.
“We had such a horrible race with a perfect end result with Lewis winning and us winning the Constructors’ Championship,” said Wolff.
“But I can tell you that mid-race we got information: power unit failure imminent on Lewis’ car.
“The guys in the background, the HPP [High Performance Powertrain] guys, fixed it. God knows how you can fix hardware that’s just about to break and make the car finish.”
Explaining how the situation unravelled, Wolff said: “We have the engine guys here in the back [of the garage] and then we have the [group] back at base.
“What I could hear, as I have about 10 channels open [on the headset], on one of the meeting channels was ‘Lewis Hamilton power unit failure imminent, it’s going to fail within the next lap’.
“And I put the volume up like ‘excuse me what?’ And they said ‘yes we have a massive problem with the power unit and it’s going to fail next lap'.
“It didn’t fail next lap and I said ‘when you guys have a minute, let me know’, so I let them work, [then asked them] to tell me what’s happening, and they said ‘well our exhaust is just about to fail as we’re overshooting all the temperature limits’.
“I asked what the fix was, so they started to fix it by turning the whole thing down.
“So the temperature went down to below 1000c, 980c, but it’s still too high, and then he recovered another lap, and that was truly horrible.”