Local hero Carlos Sainz was given a new chassis by McLaren on Friday morning as the team sought a solution to overheating problems at this weekend's Spanish Grand Prix. Sainz junior, son of double world rally champion Carlos Sainz, was unable to deliver his best at last Sunday's 70th Anniversary Grand Prix due to chronic overheating issues, which the team want to resolve for his home event. The Spaniard is in his final season with McLaren before joining Ferrari as replacement for four-time champion Sebastian Vettel next year. Race team boss Andreas Seidl said the team normally rotate their monocoques during the season to maintain even use, but had brought forward a planned change after the high temperature problems experienced at Silverstone. Seidl said: "What we have done for him here is we did different changes to the build of the car, simply to try to understand or exclude the temperature difference that we had at Silverstone. "So we changed several components, including the monocoque as well, because the radiator backs are connected to it. We want to get to the bottom of this issue." He added: "It's our task to do better here and hopefully we can start doing that from this race, his home race, onwards." str/nr