SAIC-GM, a joint venture between General Motors and its Chinese partner Shanghai Automotive Industries Corp, is recalling about 2.16 million vehicles in China because of faulty crankcase valves, the country’s quality regulator said Thursday.

General Administration of Quality Supervision, Inspection and Quarantine said the recall was ordered after Shanghai-GM received complaints about engine damage. The crankcase valves of these cars were reportedly not adequately resistant to corrosion, which could damage the engines in the long run.

The product quality agency said the affected valves will be replaced for free.

Reports said that, according to the statement, the recall applies to about 834,000 Buick Excelle sedans, 1.15 million Chevrolet Cruzes, 159,000 Chevrolet Epicas and 18,000 Chevrolet Aveos.

The vehicles were produced between Feb. 14, 2009, and April 27, 2016, Chinese news agency Xinhua reported.

According to Wall Street Journal, a spokeswoman from GM in China confirmed the statement.

The recall will start on Aug. 15.