Mercedes have confirmed that they saw nothing in their data to suggest Lewis Hamilton's Japanese Grand Prix power unit had experienced any sort of problem, after the Briton said over team radio that he felt some unusual vibrations.
Hamilton, who won the race from Max Verstappen on Sunday, had to turn his engine up in the final laps as the Red Bull driver closed up to within just a couple of tenths at one stage, before falling back as they passed through traffic.
Hamilton was then heard saying he had some vibrations, to which the team responded, "tyres or engine", with Hamilton then suggesting it was the engine.
But speaking after the race, Mercedes team boss Toto Wolff says they saw nothing to suggest their was an issue and suggested it was a psychological thing.
"We didn't see anything on the engine," said Wolff. "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 DNF'd, you hear things. The same applies for us in the pitwall or on the garage. You just want the race to finish."
Hamilton concurred: "I don't honestly think there's anything wrong with the engine," he added. "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."