In a few dozen vehicles, the fuel rail may detach and cause a fuel leak.

Volkswagen has issued a small-batch recall for 2016 Jetta, Golf and Passat variants powered by a 1.8-liter turbocharged engine.Some cylinder heads were manufactured with botched threads due to a damaged drill bit. The out-of-spec tap has been deemed potentially insufficient to properly secure the fuel rail.

"The bolt fastening the fuel rail to the cylinder head may become loose," the company warns. "Then the fuel rail may dislodge and in consequence disconnect from the injectors and allow fuel to leak out."

The German automaker lists a Mexico factory address as the component source. The damaged bit had been replaced last year prior to discovery of the problem parts, helping limit the repair campaign to just 55 units shipped to the US market.

Service technicians will be tasked with replacing the entire cylinder head in each vehicle.