Renault say they have done their best to fix the engine problems that blighted last weekend's Chinese Grand Prix but offered no guarantee on Thursday that Sunday's race in Bahrain would be trouble free.

"In the short time since the Chinese Grand Prix we have been checking and rechecking systems and procedures to implement fixes for the next race in Bahrain," said Renault sport F1 managing director Cyril Abiteboul in a statement.

"Due to logistics of the back-to-back races a complete guarantee will be difficult but we have made improvements to prevent the race stoppers we saw in China. Our motivation is as high as ever."

Former Formula One champions Red Bull scored just two points in Shanghai while their sister team Toro Rosso drew a blank after engine-related retirements.

Daniil Kvyat's race ended spectacularly with the Russian pulling up with smoke spewing from his Red Bull, while Toro Rosso's Max Verstappen brought out the safety car three laps from the end when his car halted on the main straight.

Renault have been under fire from Red Bull this season, after a 2014 season dominated by Mercedes, but Abiteboul said Renault had made real progress in performance and driveability since the opening race in Australia.

"It's frustrating that the reliability issues of Shanghai threw a cover over these," he said.

"We don't take the issues we have seen lightly, but we have taken genuine steps forward and need to focus on our continuing programme of improvements while addressing the reliability concerns in parallel." – Reuters