BMW of North America added nearly185,000 vehicles in the U.S. to a 2017 recall involving the risk of engine fires.
The company issued a recall in 2017 that covered 740,000 2007-11 vehicles with a valve heater that could rust and lead to fire in rare cases. The additional recall brings the total number of affected vehicles to about 925,000.
The recall expansion covers 3-series, 5-series and Z4 models from the 2006 model year.
BMW said in documents filed with the National Highway Traffic Safety Administration that the blow-by heater, which is designed to prevent the engine's positive crankcase ventilation system from freezing, can short-circuit. Irregularities in the manufacturing process could allow moisture to occur near the blow-by heater and lead to the short-circuit.
Consequently, the short can cause the parts within the positive crankcase ventilation valve to melt, increasing the risk of a fire, even when the vehicle is not in use, BMW said in the documents posted Thursday.
BMW found "several field incidents" involving 2006 3-series vehicles, so the company decided to add to the recall from November 2017. BMW said it is not aware of any accidents of injuries related to the issue.
The 2016 vehicles added to the recall were the 525i, 525xi, 530i, 530xi, 530xi wagon, 325i, 325xi, 325xi wagon, 330i, 330xi, Z4 3.0i and Z4 3.0si.
BMW will notify owners, and dealers will replace the PVC valve heater. The recall is expected to begin May 28.
Reuters contributed to this report.