Daniel Ricciardo flamed out of the Italian Grand Prix as his frustrating patch of the Formula One season continued.
The Red Bull star's race ended on lap 25 of 53 at Monza when smoke began to billow out of the back of his new engine after overtaking Williams' Sergey Sirotkin for 11th place.
"I got smoke. I got smoke. I don't know what it is," Ricciardo pointedly said over the team radio.
"I heard something breaking for one [thing]."
But the mostly happy-go-lucky Western Australian still found time to make light of the disappointing situation.
‘‘If I’ve got a penalty in Singapore I’m probably not even going to show up,’’ Ricciardo joked post-race to Sky Sports.
Although it was initially thought to be an engine issue, the constructor later confirmed the fault was clutch related.
"We can confirm, after studying the PU on Daniel Ricciardo's car, that his retirement was not linked to the engine," Renault said in a statement.
"It was rather a clutch issue."
It's the fourth time in his past six races that the Australian ace, on the move to Renault for next season, has failed to finish due to mechanical faults.
"It's been another frustrating race for me," Ricciardo told the Red Bull Racing website.
"I feared it could have been something to do with the power unit but after we got the car back to the garage and the guys investigated, they suspect it's a clutch issue.
"It's been a frustrating period of races but hopefully we can change some things on the car, improve the reliability and aim for the podium in Singapore."
Ricciardo started at the rear of the grid in 15th due to penalties for swapping to a new engine power unit.
His latest DNF leaves him 138 points adrift of drivers' standings leader Lewis Hamilton, who held off Finnish duo Kimi Raikkonen and Valtteri Bottas for his sixth win of the season.