Barcelona Testing – McLaren and Red Bull have both faced early issues in the first hour of pre-season testing.
The MCL32 completed its 100km filming day mileage allowance without any problems, but Fernando Alonso returned to the pits after his installation lap on the first day of pre-season testing at Barcelona with an issue on his car.
“We have an oil systems issue which requires a full investigation,” a McLaren spokeswoman said.
“We plan to run again today, but due to the difficult access location it will take several hours to resolve.”
The issue is at the very front of the engine, which is expected to take 4-5 hours to dismantle.
Honda have radically redesigned their engine in a bid to catch up with the top engine manufacturers. They have adopted the split turbo design Mercedes pioneered at the start of the hybrid era in 2014.
Red Bull, meanwhile, were the first team to bring out the red flags as Daniel Ricciardo stopped on track on the exit of Turn 3 on only his fourth lap.
The team are blaming a sensor issue for the stoppage. Sister team Toro Rosso faced an ERS failure during their filming day on Wednesday.
Ricciardo had set a lap time of 1:28.712 before he stopped on track.