And what's the actual problem with the engine?
Defect in manufacturing left potential for debris that could cause the engine to sieze/stall, if I understand correctly. Last I read, no examples of the engine failing have occurred.
Your understanding of how engines work is what's letting you down here. You simply can't tell there is a widespread issue of debris in the engine UNTIL THEY FAIL, usually. For example, any one of your cars could have debris in it right now. But you have no idea. Until the debris gets stuck in the oil filter/oil passages (most likely issue) and the engine fails.
GM had a similar issue in the Corvettes. And they had no idea until several engines failed. But they rectified the issue immediately.
Now the caveat to this (and why they might be subject of investigation) is that oil changes are being found with large metal debris in them (however, I doubt this. Ever see how the do an oil change at a dealer? They just pop the plug and drain it into the large funnel. Not much investigating is happening during an oil change).. In which case the dealer would call Hyundai (which is usually the case for stuff like this) and Hyundai did not act quick enough to look into the issue. OR, if the engines were indeed failing, in which once again the dealers contact Hyundai (often, major failures like engines get called in..both for warranty reasons and for quality reasons) and Hyundai didn't act quick enough to remedy the situation.
And to give you an idea of how small oil passages are, they are usually 4-5mm. That's small. But the engine debris could be even smaller...and a number of tiny particles could end up clogging the oil passages. Debris small enough on their own that you might not even see in an oil change. But collectively, enough to plug up a passage.
