Formula One team Red Bull Racing is fearing that a 'ticking time bomb' could blow Sebastian Vettel's world championship bid to pieces.
The worry follows team-mate Mark Webber's exit from the US Grand Prix due to an alternator failure.
It is a recurring problem for the Renault-powered squad and they are hoping that it will not strike Vettel in Sunday's title-deciding race in Brazil.
"Reliability is a concern. This was unfortunately our third alternator failure this year, which is a ticking time bomb. The cars are very complicated and keeping them going round is anything but guaranteed," the Daily Mirror quoted Red Bull's technical chief Adrian Newey, as saying.
"You never know when that one is going to strike. Renault haven't managed to find a proper solution so that's a continual worry in the back of our minds, as is the rest of the reliability," he added.
Team principal Christian Horner hopes they will have the new version for Interlagos, while Vettel is confident the team will resolve the issue.
"We have managed the last couple of races pretty well so I'm sure it should be easy to find the problem," he said. (ANI)