DETROIT (AP) -- BMW is recalling more than 1.4 million cars and SUVs in two U.S. recalls due to the risk of fires under the hood.

The biggest recall includes over 740,000 328i, 328xi, 328i xDrive, 525i, 525xi, 528i, 528xi, 530i, 530xi, X3 3.0si, X3 xDrive30i, X5 xDrive30i, Z4 3.0i, Z4 3.0si and Z4 sDrive30i vehicles from 2007-2011. Also included is the 2008-2011 128i.

Documents posted Friday by the U.S. National Highway Traffic Safety Administration show that a heater for the positive crankcase ventilation valve can overheat and cause the valve to melt, increasing the risk of a fire even when the vehicle is not in use. No injuries have been reported. Dealers will replace the heater.

The second recall covers nearly 673,000 cars including the 323i, 325i, 325xi, 328i, 328xi, 330i, 330xi, 335i, 335xi and M3 from the 2006-2011 model years. Also covered are the 2007-2011 328i xDrive, 335i xDrive and 335is, and the 2009-2011 335d.

Wiring for the heating and air conditioning system can overheat and cause connectors to melt, also increasing the fire risk, even when vehicles are unattended. Four drivers reported injuries.

Dealers will replace the wiring and connectors. Both recalls begin Dec. 18.