Oops, they did it again.
“Hyundai says machining errors occurred when the engines were built and those errors can cause the engine bearings to wear out early. Those prematurely worn bearings will cause the engine to lock up, something a dealer will need to fix by replacing the engine short block.”
Metal debris is accumulating in the crankshaft of Theta II engine during the machining process. For some reason, Hyundai can’t seem to remove all the debris before the engines are shipped.
From there it’s only a matter of time before the debris is grabbed by oil → the oil starts to clog up → the reduced flow affects the connecting rod bearings → heat and friction rise → the bearings wear out prematurely → horrible knocking noise ensue.
If they aren’t dealt with in time, the bearings will eventually fail and cause the engine to seize.
The recalled vehicles include the 2013-14 Hyundai Sonata and Santa Fe Sport.