McLaren have been forced to end the first day of the second test early with Jenson Button completing just 21 laps during the morning.
The team discovered a faulty seal on the MGU-K which requires a full power unit change – something that will need to be done during the afternoon.
However it’s likely the issue will occur again during Friday’s running with Fernando Alonso as a proper fix won’t be available until Saturday according to Honda’s Yasuhisa Arai.
“That faulty part caused an issue that requires full replacement of the power-unit – and the time needed to make those changes effectively ends today’s programme.
“We’ll need to run a redesigned component to avoid a potential repeat of the problem.
“Unfortunately, we won’t be in possession of that updated part until Saturday, which means that we may face the same problem when we run again tomorrow.”
The team enjoyed their best morning yet with Button completing 21 laps. However the problem is yet another blow with the team urgently needing as much mileage as possible.
