There’s an argument to be made that auto mechanics are straight up modern day magicians, who with a combination of intuition and a little poking around can diagnose and fix any problem plaguing your car or truck.
Case in point: TikTok creator Motorcarnut (@motorcarnut), whose name isn’t made public on his social accounts, so for the sake of brevity and readability we’ll refer to him as “Sparky.” In one of his newer videos, Sparky gives us the inside insights on what’s causing the rod knock on the engine he’s working on. At the start of the clips he says both Kia and Hyundai engines suffer from the same issues he’s about to pinpoint, but he doesn’t disclose what make or model the engine in question came out of.
Why do Hyundai and Kia engines fail?
That said, he goes on to pin the blame on “oil starvation,” which he suggests is frequently caused by negligent owners who don’t detect oil leaks or keep fresh oil in their vehicle. In the engine he’s trying to fix, though, Sparky said that poor manufacturing practices by the automaker are the culprit.
“It’s the manufacturing of the crank at the factory when they drill the holes for the oil passages,” he said, while moving close to view the different cylinders.
“Over here… you have a nice oil passage. This (other) one failed. This one has a rod. This one has a knock.”
For those who don’t speak fluent greasemonkey, rod knock is a fairly obvious clicking or smacking sound that happens when a car is idling. The rod in question is the connecting rod for the crankshaft and the pistons that power the engine. When the connecting rod comes loose it wears, makes knocking noises, and is likely on its way to total engine failure if not fixed quickly.
When Sparky runs an air compressor through a working oil passage it’s clear there’s air moving around and environment where oil can flow to keep things lubricated.
For the chamber on the other end, though, you hear nothing.
“You put air in here, nothing. That’s because when they machine it, all the filings, they don’t clean them out enough. They build up usually to one area. Now this has no oil circulating through it. And what happens? It blows out, and that’s why it just totally destroyed the bearing in here.”
Worth noting: Problems with engines in more than a dozen Kia and Hyundai models made at various time periods from 2010 through 2020 were included a recent $3.1 billion class-action suit. It’s unclear if the issues details in that legal action are the same as the problem Sparky highlighted in his video clip.
The post’s comment section had plenty of war stories from the auto world of mechanics and assembly line workers.
“It’s a problem in machining. I’ve worked in machining for Ford 24yrs. If you don’t have the right cleaning and debris cleaning tools on the line a small build up easily happens,” one commenter posted.
Another testified to how common engine problems can be on some cars: “I know a girl that has been through 4 engines under warranty.”
And one former Hyundai owner explained why they’d made a permanent switch, writing “Had a Hyundai that oil was changed every 3000 miles like clockwork, locked up at 56,000 miles. Done with both brands! Toyota only now!”
The Daily Dot has reached out to Motorcarnut via direct message and to Hyundai, parent company of Kia, via email.