McLaren are facing up to another pre-season crisis after their car broke down three times on the opening day of this week's concluding Formula One test.
Stoffel Vandoorne had two electrical issues inside the first hour at Barcelona's Circuit de Catalunya - which on both occasions resulted in his mechanics pushing him back to the pits - before a hydraulics failure cost the British team further valuable time later in the day.
Vandoorne stopped at turn three shortly before 4pm local time and never returned to the track. By the end of eight hours of testing on Tuesday, McLaren had completed just 38 laps.
In contrast, Lewis Hamilton's Mercedes team clocked up a mammoth 174 circuits, while Ferrari's Sebastian Vettel was not far behind. Red Bull's Max Verstappen also finished well past the century mark.
McLaren are hoping to return to the sharp end of the grid this season following their decision to divorce from Honda and switch to Renault power, but their winter campaign has been blighted by a series of reliability issues.
A faulty wheel nut wrote off an entire morning for Fernando Alonso on the first day of testing in Barcelona last week, while Vandoorne did not complete any laps during the afternoon running on the second day following a broken exhaust clip.
Toro Rosso, the team which is now powered by Honda, enjoyed a relatively trouble-free day and Frenchman Pierre Gasly managed 54 laps on Tuesday.
McLaren chief Zak Brown was in Switzerland on Tuesday as he attend Geneva's International Motor Show.
The American attempted to put a brave face on his team's troubles, but he will be concerned by what he has seen so far this winter with just three further days of testing before the season gets under way in Melbourne on March 25.
McLaren, a winner of 20 combined drivers' and team titles, finished last but one in the constructors' championship in 2017 and have failed to win a race in six years.
Their star driver Fernando Alonso, who agreed to stay at the team this year on the proviso they would be front runners once more, will test for the Woking marque on Wednesday.
Vettel ended the day on top of the timesheets for Ferrari ahead of Mercedes' Valtteri Bottas and Verstappen. The trio were separated by less than a third of a second.
Hamilton, who took over testing duties from Bottas after the lunch break, was fourth fastest.