Mercedes: No concerns about Hamilton's engine

Hamilton came on the radio following the chequered flag to say that he had experienced a vibration with his power unit in the latter stages of the Japanese Grand Prix, and that he had been short-shifting.

Hamilton's issue prompted suggestions that that Mercedes engine could have hit trouble.

But speaking after the race, Mercedes motorsport boss Toto Wolff said that the team's telemetry had indicated that there was no issue at all with the power unit.

"We didn't see anything on the engine," he explained. "We looked at all the metrics. We need to really understand what he meant.

"My assumption is that when you are in the lead, and your main competitor has DNFed, you hear things. The same applies for us in the pitwall or on the garage. You just want the race to finish."

Hamilton later suggested that his message over the radio was more a way of reminding his team to double-check the engine situation, rather than because he was unduly concerned about matters.

"I don't honestly think there's any wrong with the engine," he said. "I just felt a couple of things so I just… you just point out things that you might forget to tell them after this next meeting.

"You make lots of different switch changes and the turbos make strange noises and different vibrations come in, so I'm hoping there's nothing.

"I don't think there is anything, I think it was just low… short shifting which the engine doesn't like so much. So I think that was it."

Championship rival Sebastian Vettel retired from the race with a spark plug failure, and it has emerged that Mercedes had to change a faulty spark plug on Hamilton's car after qualifying because it had discovered a problem with it.