The team said in a statement that the move was with immediate effect.
Goss, who joined eight-times Formula One constructors' champions McLaren as a development engineer in 1990, was previously the team's director of engineering.
The season starts in Australia on March 17 with Mexican Sergio Perez joining Britain's Jenson Button in the McLaren lineup after the departure of 2008 world champion Lewis Hamilton to Mercedes.
Lowe has been tipped to follow Hamilton, with media reports last month suggesting he could ultimately replace Ross Brawn as Mercedes principal.
Brawn, who will be 60 next year, said last month that he was planning on being at Mercedes for a long time but was also building a succession plan at a team that won championships under his name as Brawn GP.
McLaren team principal Martin Whitmarsh said Lowe, who can expect to face a period of 'gardening leave' keeping him away from the team's 2014 car, would have a different role until the end of the year.
Lowe was already conspicuous by his absence when the new McLaren was launched at the Woking factory last month.
"He's been a good and successful F1 technical director and we wish him well when he embarks on a fresh challenge in 2014," Whitmarsh said in the statement.
The Formula One rules are undergoing a major overhaul in 2014, with a new V6 turbo engine and energy recovery systems replacing the current V8s.
Mercedes, who have struggled in their three years back in F1 as a team, hope to have an advantage as an engine manufacturer.
Whitmarsh said Goss's promotion was a "natural evolution" in his career and he was not to be underestimated.
"His quiet and unassuming persona conceals a fierce competitiveness and a wealth of experience, coupled to an unrivalled level of expertise in the field of Formula One car design and engineering," he said.
"It's a little-known fact, for example, that over the past 23 years he's made crucial technical and engineering contributions to the winning of five of McLaren's 12 drivers' World Championships and three of McLaren's eight constructors' World Championships.
"He's been the principal definer and developer of McLaren's F1 car design function for more than five years," added Whitmarsh.
