Revealed: The cause of Isack Hadjar’s Australian GP retirement on Red Bull debut

Red Bull driver Isack Hadjar suffered a power unit failure prior to his retirement from last weekend’s Australian Grand Prix, an initial investigation has confirmed.

Red Bull, which is producing its own engines for the first time this season via its in-house Powertrains division, had a mixed start to the F1 2026 campaign in Melbourne last weekend.

Red Bull PU failure behind Isack Hadjar DNF at Australian GP

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Hadjar qualified an impressive third on his debut for Red Bull Racing before retiring after 10 laps of the race.

Meanwhile, four-time world champion Max Verstappen failed to record a lap in qualifying after crashing at the first corner of his first Q1 effort.

He recovered to sixth on race day, but trailed the race-winning Mercedes of George Russell by almost a minute.

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PlanetF1.com understands that an investigation into Hadjar’s stoppage has confirmed that a power unit failure was the cause.

It is believed that the team’s investigation remains ongoing ahead of this weekend’s Chinese Grand Prix, with it yet to be determined which engine components can be retained in Hadjar’s pool for the F1 2026 season.

Speaking to PlanetF1.com and other media outlets after his retirement, Hadjar revealed that he thought he would take the lead at the first corner after getting a better start than the Mercedes pair of George Russell and Kimi Antonelli.

However, he was suddenly left with “no more power” just as he felt he was heading into the lead.

Hadjar said: “The start was amazing.

“I started the race with no battery, so the launch was a very good launch. I was taking the lead easily, so that was at least a good point of the day: we have very good starts.

“Once I thought, ‘Oh, I’m going to take the lead’, no more power. So that was great.

“And so, you can imagine, for couple of laps I’m spending time to just recover.

“Engine sounded terrible, so I knew I was not going to finish the race.

“It’s a shame. I think I was going to be the mix with Lewis [Hamilton, who finished fourth].”

A number of other drivers struggled for power off the line, with PlanetF1.com reporting on Tuesday that Verstappen had an “almost empty” battery for the race start.

Hadjar clarified that his lack of power at the start was not related to the issue that ultimately ended his race.

He explained: “No, it’s not a technical issue.

“We need to do better to avoid this from happening. We didn’t manage to simulate it in the whole six days of testing, in free practice as well, so honestly it’s just new scenarios.

“A race scenario is different. It’s good experience at least.

“We had a very smooth weekend so far [until the DNF].

“When you do practice sessions with these young engines, they are not as demanding as a race procedure, laps to the grid, staying still, temperatures going up and down, so it’s very difficult for the guys.”

Hadjar had a brief fight with Racing Bulls debutant Arvid Lindblad in the early stages of the race, quipping that it was his “only highlight” of the Australian Grand Prix.

He said: “It’s hard to fight someone who’s going 30pkh faster than you on the straight. That was my only highlight of the day.”

Asked how he has settled into life at Red Bull’s senior team after becoming Verstappen’s new teammate for 2026, he added: “Honestly, I felt great out there. Just zero mistakes all weekend. Very comfortable.

“It’s a shame. I wish I could be still on track fighting for third.”

Additional reporting by Mat Coch and Thomas Maher

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