Suzuka - Fernando Alonso will incur a 35-place grid penalty and start this weekend's Japanese Grand Prix last after changing his engine, McLaren said on Saturday.
Mercedes driver Valtteri Bottas will also receive a five-place grid penalty after the Finn was forced to make a gearbox change to his car.
McLaren broke a late-night curfew to switch components to the Honda power unit after discovering a hydraulic leak after Friday practice at Suzuka.
Alonso's struggling car will now have its eighth engine of a troubled season, its 10th turbocharger and seventh battery, among other changes, for Honda's home race.
The penalty sends the double world champion to the back of the grid alongside fellow Spaniard Carlos Sainz, who was hit with a 20-place penalty for changing his Renault engine.