Honda F1 engine troubles in first test a surprise for McLaren

Fernando Alonso only managed to complete an installation lap on the first morning of F1 testing at Barcelona on Monday, after an oil system problem left him sidelined.

There were further mechanical hiccups with a fresh engine that was fitted in the afternoon as the team finally managed to get some laps on the board.

But rather than view that stuttering start as a precursor to fresh troubles with Honda - ahead of the third season of its current programme - McLaren racing director Eric Boullier said the situation was slightly baffling because Alonso completed 100km without issues 24 hours earlier.

"We had an oil system problem and that is all we know now," said Boullier, when asked by Autosport about the team's situation.

"Honda has asked for the power unit to be sent back, and they are investigating what is going on and Honda will tell us what happened.

"It is obviously disappointing because yesterday we had a filming day, we did our 100km and more or less everything went right, so today it was a bit of a surprise to have this problem with the power unit.

"But we have to wait for Honda to come back to us."

Asked how Honda had reacted, Boullier said: "I think they reacted as professional as you would expect.

"They were disappointed and rather than obviously driving everybody nuts around they just sat down, organised calls with Sakura in Japan and also we had some meetings together with us: just to start to maybe help an investigation, and also to decide what to do.

"This is why we decided to work together to take his PU off the car to let's say not let any suspicious thing stay on the car."

With good progress from Honda expected to be key to Alonso's future at McLaren beyond 2017, Boullier admitted the troubles were not ideal.

"Obviously [Alonso] knows minute after minute what is going on, so he was not very happy this morning," he said.

"But he was here yesterday so he drove the car yesterday for a few laps and he got a feel for the car, and I guess he was rather happy than unhappy yesterday. That is what he felt.

"This morning was obviously unexpected and this is what it is."

Boullier insisted the difficult start did not share any similarities with Honda's troubled preparations for its F1 return campaign in 2015, and suggested the matter would not put fresh strains on the team's relationship with its Japanese engine partner.

"I think it is like any marriage: you can have some ups and downs," he said.

"So far we went through a lot of stress in the last couple of years but we have built a positive and constructive relationship, so I don't expect this to change for the future."