Mercedes still investigating Hamilton's engine failure

The Briton's championship hopes took a big hit at Sepang after his engine blew up when he looked set for a comfortable victory that would put him back on top of the standings.

However, the retirement meant Hamilton now trails teammate Nico Rosberg by 23 points with five races to go.

Mercedes technical chief Paddy Lowe said the team was still investigating the engine to find out what had gone wrong.

"Malaysia was a bitter pill to swallow. We let Lewis down in a big way," said Lowe in a team preview ahead of the Japanese Grand Prix.

"We are continuing to investigate the issue with his engine and are doing everything we can to ensure that it is first understood and then contained for the remainder of the season.

"As it stands, despite the failure of this engine, Lewis now has the same stock of power units as Nico for the remaining five races - including used power units which he can fit for free practice sessions.

"So, hopefully there will be no further impact to his programme."

Team boss Toto Wolff insisted there was no pattern to Hamilton's problems this year.

"There is no rational explanation or pattern in these failures. If there were, we would resolve it," Wolff said.

"We've had that discussion with him and he understands that we are feeling his pain too."