Cosworth is not in Rubens Barrichello or Lucas di Grassi’s good books at the scene of the Turkish grand prix.
Williams’ Rubens Barrichello, just fifteenth on the grid at Istanbul Park, said the British team is "suffering" from a lack of power.
"The engine that we brought did not work," he is quoted by Brazil’s Globo. "The straightline speed is not good."
Lucas di Grassi is also unhappy, having been outqualified by Bruno Senna of the struggling HRT team.
"My lap was good," said the rookie, who is finally at the wheel of Virgin’s updated VR-01 car this weekend.
"The car was good in the corners, but the engine was not working on the straights or in acceleration."
Di Grassi will have a fresh engine fitted for Sunday’s race.