Red Bull Racing boss Christian Horner is pointing the finger once again at engine partner Renault for failing to deliver a reliable product.
While Daniel Ricciardo made the most of yesterday's Belgian GP in which he achieved a third-place finish, team mate Max Verstappen retired early on with an engine problem.
The Dutch teenager has been on the receiving end of Renault's reliability issues this season more often than he cares to remember, and Horner isn't happy.
"Renault are quite aware that their reliability and product isn’t where it should be," said Horner.
"It’s their business to sort that out. We’re a paying customer and it’s obviously below par the service we are seeing at this point in time because [of the] reliability issues, the failures.
"We pay a hell of a lot of money for the engine. They need to sort it out.
"It’s hurting them as much as it is hurting ourselves. At this level, you can’t afford the kind of failures that we’re consistently seeing."
The source of Verstappen's failure was believed to be linked to a sensor or spark plug issue which shut down one cylinder.
But Red Bull wasn't the only team which dealt with Renault weakness over the Spa weekend, with Toro Rosso and the works outfit also seeing failures.
"Reliability across the three teams is pretty dire," said Horner.
"Turbo failures with Kvyat, engine replacements that have had to happen with two cars as we come here.
"It’s not great, it’s far from great and it’s not the level an engine supplier which wishes to be competitive in F1 should be at.
"They are working hard at it and hopefully putting in place process to avoid the kind of issues that we are seeing."