Automotive News, citing unnamed sources, reported the Detroit-Hamtramck plant will suspend production from Sept. 17 until Oct. 15. Leaders of the UAW told the plant's 1,500 union workers about the scheduled downtime last week, the source said.

 

While it would be the second interruption in this year production for the Volt, but GM late Monday broke from its usual practice of not commenting on production to dispute the report that the move is because of slow Volt sales. It said it was to ready the plant to build the redesigned Impala starting in the first quarter.

"We are not idling the plant due to poor Volt sales. We're gearing up for production of the new Impala," Chevy spokesman David Darovitz said in an email. The 2014 Impala, a complete redesign, is a key model for Chevy, and GM wants to take extra time preparing the factory to ensure a high-quality launch, Darovitz said.

Volt sales this year are 10,666 through July, way up from the period a year ago in which GM sold 2,870 of the cars,which can go 38 miles on battery power before needing charging from its gasoline engine. Production was suspended last spring when inventories increased well ahead of demand, but the supply on dealer lots has since been cut almost in half to a more acceptable 85 days worth of cars, according to Auto News.