MANAMA, April 16 (Reuters) - Stoffel Vandoorne failed to start the Bahrain Grand Prix on Sunday, a year on from his Formula One debut at the desert track, as engine woes continued to plague former champions McLaren.
McLaren said the Belgian rookie, who had qualified 17th, had been ruled out by a power unit problem similar to those he suffered in Friday practice.
McLaren are last in the standings, without a point from two races and hampered by woeful reliability and a lack of power from their Honda engine.
Double world champion Fernando Alonso, who also had an engine failure in qualifying, started 15th but with little optimism.
Honda's motorsport head Yusuke Hasegawa said on Saturday that the Japanese manufacturer was not sure of the exact cause of the failures.
"It is something around the bearings, it was sticking. It happened (three) times here, which is very unfortunate," he told reporters.
Alonso, asked about the driveability of the engine, was withering in response: "I don’t care too much about the driveability if I can’t finish a race or a lap in qualifying now."
Vandoorne finished 10th on his debut in Bahrain last year as a one-off replacement for Alonso, who had been ruled out by a big accident in the opening race in Australia.
McLaren, who have not won a grand prix since 2012, were sixth overall in 2016 after ending the previous season in ninth place. (Reporting by Alan Baldwin, editing by Pritha Sarkar)