Over the past couple of weeks, car manufacturers have been recalling millions of cars due to various defects. Now another carmaker joins the growing list of companies ushering a recall of certain products. Although this recall is not of the same proportions as General Motors or Toyota's, it still casts doubts about the company's quality control.

The German carmaker BMW made the announcement on Thursday that it was recalling 156,137 luxury cars in its American market, according to USA Today. The recall was issued because bolts holding a component of their six-cylinder engines can fail and cause the engine to stall or be damaged.

BMW notified the National Highway Traffic Safety Administration of the defect. They stated, however, that it happens only in rare cases. If there is a malfunction, the bolts holding the housing for the variable camshaft timing unit can become loosened or broken, causing the engine to go into "safe mode," thus lowering engine performance. When this happens, the "check engine" or "service engine soon" lights will turn on. Continued use of the car after the bolts give way, USA Today reports, will lead to the engine stalling.

The recall is in fact an extension. According to Bloomberg, it all started in China where a repair program had begun to address the bolt issue. Over 232,000 cars are affected in China and were recalled in the last month. Yet, the recall now has been expanded to 489,000 cars, including the American cars recalled.

Though BMW spokesman Berhard Santer did not specify the models being recalled, Bloomberg notes that most of BMW's lineup is available with the six-cylinder engine in question. The 7 series, 5 series, 3 series, X3 and X5 all use the engine.

In a press conference on March 19, BMW's head of research and development, Herbert Deiss, said that the company's data on breakdowns and guarantee services show quality is at a "good level." He added that the number of recalls has not significantly changed but the numbers of cars per recall has increased.