(December 14, 2019) Subaru has issued two U.S. recalls for 671,225 Subaru Impreza vehicles over loss of power issues. In one recall, which includes 205,000 model year 2017-19 Impreza vehicles, the positive crankcase ventilation valve, an oil flow control device, could separate and allow engine oil to enter the combustion chamber, NHTSA documents said.

With continued driving in this condition, components of the valve may enter the engine causing a loss of power. Drivers may notice a visible change in the appearance or amount of tailpipe exhaust, the documents said.

The recall documents said 41,282 of the vehicles affected are Impreza four-door vehicles, and 80,219 are Impreza station wagons.

Affected vehicles are equipped with an aluminum valve case "with an insufficiently assigned press force value," NHTSA documents said.

Subaru also issued a recall for 466,225 model year 2017-2020 Impreza vehicles that may have improperly programmed Engine Control Modules.

"Under certain circumstances," the ignition coil could stay energized "longer than designed" after the engine is turned off, NHTSA documents said. If energized for too long, the ignition coil's internal temperature may increase, causing a short circuit and blown fuse.

A short circuit while the vehicle is in motion may cause loss of power "without the ability to immediately restart the engine," documents said.