Engine fires are forcing General Motors to recall the Chevy Cruze, a popular model that has helped GM win back small-car buyers. The recall covers 475,000 vehicles made in the U.S. from September 2010 to May 2012. It’s the car’s fifth recall since it arrived in showrooms nearly two years ago, raising questions about the sedan’s reliability. The fires can break out when fluids drip onto a hot plastic shield below the engine. The problem occurs mainly when oil is spilled and not properly cleaned up during changes, GM said Friday.