Formula 1 world champion Lewis Hamilton was hit by a loss of power in qualifying for a second straight grand prix in Russia.
After being consigned to a last-place start in the previous event at Shanghai, this time Hamilton got to the end of Q2 before the MGU-H problem hit his Mercedes.
He had headed out to try to reduce a half-second deficit to team-mate Nico Rosberg in Q2 when he noticed the issue.
Mercedes called him in and immediately announced he would have to sit out Q3.
"This is the second engine that I took from the last race and it's the same failure as I had in the last race," said Hamilton.
"Ij ust went back out in Q2 at the end to get a feel for the lap and I lost the same power as I lost in China.
"Nothing I can do."
Rosberg went on to take pole position by a comfortable margin.
Mercedes decided the engine that suffered the problem in China was fit to be re-used as a spare in Russia.
The team is not yet sure whether Hamilton's car will require any further replacement components overnight that could result in extra grid penalties.