F1 commentator reveals the possible cause of Mercedes engine problem

In the preview on Ziggo Sport, the F1 commentator says: "At Mercedes they are shouting, 'No, it's different, we have another problem with the pneumatic valves. I heard that from Karun Chandhok. He said to me that he knows someone who works on those engines at the factory. That seems to be the problem."

Workings explained

Valve springs used to be used in Formula 1, but pneumatic valves have been used for some time now. "So basically they push those valves down with a puff of air and with a vacuum, they are brought back up again," Mol explains the operation. "There's a bottle on there, there's 200 bar open. That is so high. You'll never get that closed perfectly, also because air has to go out."

He continues: "Five percent leakage, they can ride out a whole race on that, that's all okay, but when it goes towards ten percent (like with George Russell in Austria) then you have to stop. Then you see one of those guys go in with a bottle and they re-pressurise the system to keep the engine running."

Mercedes practising in the meantime

Mol says that the Mercedes pit crew in Austin are prepared for this to happen during Sunday's GP. "Yesterday at a pit stop in free practice they did the same to Hamilton. It's said that they did that because they think that's where the problem is and they might have to start doing that in the race. So then you can see how much time that will cost you. It's deep in the engine, technically hidden."