Hyundai re-recalls 100K vehicles, adds software to detect engine failure

The knock sensor is used to detect engine bearing wear in over two million vehicles powered by engines produced in the US.

Hyundai has issued a follow-up recall for around 100,000 Sonata and Santa Fe vehicles that received new engines in an earlier campaign, while a software update will help detect signs of engine bearing wear.

Related recalls launched in 2015 and 2017 affected millions of vehicles powered by Hyundai's Theta II engine. A manufacturing error had left metal debris in oil passages, causing connecting rod bearings to fail due to oil starvation.

Some of the vehicles that received brand-new engines may have been improperly reassembled. In some cases, the high-pressure fuel pipe may have been damaged, misaligned or improperly torqued, allowing fuel to leak. Hyundai will reinspect 100,000 vehicles to ensure proper reinstallation of the fuel tube.

Notably, the NHTSA in 2017 launched an investigation into why the Korean automaker waited two years after the 2015 recall to expand the campaign and add newer model years that were affected by the same problem.

Now, Hyundai is launching a preventative "product improvement campaign" that will install monitoring software on over 2 million Sonata and Santa Fe Sport vehicles from the 2011-2018 model years. The company has developed a method using the knock sensor to detect vibrations that indicate premature bearing wear. If the system flags a problem, the engine will be put into a limp mode limited to 60-65 mph and 1,800-2,2000 rpm until the car can be taken in for inspection.

The company is also rolling out an extended warranty for vehicles that utilize the new software, bumping the engine-replacement coverage to 120,000 miles from the previous cap of 100,000 miles.