Pérez had lapped very close to Carlos Sainz in the opening laps of the race, and was threatening to attack and steal third place from him in the grand prix finish before his engine lost power.
The problem was attributed to a sensor failure that caused some systems to shut down automatically, and the team’s engineers had to reprogram it to keep it working.
Despite the continued loss of power, Sergio Pérez managed to follow Sainz to the finish and finish fourth, having attempted, on new medium tyres, an overtake gone wrong at Turn 1.
But after the race, Red Bull team principal Christian Horner confessed that the sensor problem was so big, it was not clear that the Mexican would see the checkered flag.
“It was very close,” Horner said of the risk of a DNF. “We had to move the sensors to fix the problem. So that’s something we’ll be working closely with HRC [ Honda’s engine division ] to try and understand and obviously make sure it doesn’t happen in the future.”
Horner explained that the problem with the sensor was in the internal combustion engine (ICE) and cost Pérez a significant lap time.
But it especially affected his top speed, which did not allow him at the end of the straight to overtake Sainz in the last laps.
“He had a problem with a sensor on one of the cylinders,” Horner added. “The guys managed to move the sensors, but as a result, it probably lost 20kw of power.”
“Even with the advantage of the new tire that I had, I was probably half a second short of what the car was capable of on the straight. And I think without that I probably would have even been second.
Although Perez’s sensor failure is the latest in a series of reliability issues that have plagued Red Bull this term, Horner doesn’t think the team has much to worry about on that front.
“I don’t think the car is particularly fragile,” he said. “I think there have been annoying things that you normally would have seen in pre-season testing, but have only reared their heads as we’ve gone through the season,” he said.
“That has been frustrating. But we are working closely with HRC and they are giving us great support. So I think we will fix them.”
