Why the oil drain plug falls out of your Hyundai or Kia

Even when properly tightened, the oil drain plug on your Hyundai or Kia can still fall out

The National Highway Traffic Safety Administration has launched an investigation into why the oil drain plug falls out of Hyundai and Kia engines even when the oil drain plug is properly tightened.

In October 2022, the National Highway Traffic Safety Administration (NHTSA) announced it had launched an investigation into Hyundai Motor Company and Kia Motor Company for problems with their oil pans and oil drain plugs. Specifically, consumers and aftermarket service facilities have filed complaints their engine’s oil drain plug falls out, causing all the oil to drain out of their engine while driving.

In multiple tests the oil drain plug was tightened according to factory torque specifications and the tightening was well documented. Yet, testing shows in multiple cases that while driving, the oil drain plug falls within a few thousand miles after the service. In those cases, the crankcase drained completely.

The Hyundai and Kia drain plug falls out due to inferior oil pan material and the drain plug gasket

The testing and investigations appear to show that the oil drain plans are made with thin metal and the drain plug mounting port is poorly reinforced. In addition, the oil pan is coated with a thick paint coating the bonds the gasket to the pan, so the gasket does not come off when the drain plug is removed. That gasket issue alone is not why the oil drain plug falls out, but it is a factor in the chain of events.

The oil pan is the biggest problem

Apparently, the thin metal, along with engine vibrations and expansion/contraction tend to loosen the drain plug without any other intervention. NHTSA is investigating this as a factory defect issue.

The problem is two-fold. First, even if the repair shop properly torques the drain plug, the oil drain plug falls out on its own. The customer then blames the shop for shoddy workmanship.

Second, Hyundai and Kia dealers are telling customers that servicing their vehicle at an aftermarket shop automatically voids their factory warranty. This is totally false and actually illegal under the terms of the Magnuson-Moss Warranty Act.

What to do if your Hyundai oil plug or Kia oil plug falls out

First, contact the dealer to see if they’ll cover the damage. If they deny coverage based on the fact that the oil change was performed at an aftermarket service facility, demand that they put the denial in writing. This will help later in arbitration or if you have to sue. It may help to remind the dealer that this is a known issue, that the NHTSA has launched an investigation and that what they are telling you is illegal.

Next, file a formal complaint with NHTSA. In your complaint include the receipt from the oil change facility, the date the plug fell out, towing bills, repair estimates and recording or written documentation from the Hyundai or Kia dealer denying warranty coverage.

Third, get your vehicle repaired. Keep all your receipts because this process may drag on for years before you get reimbursed.

Some steps to avoid engine failure

1) Have your oil changed at the dealer. That way there can be no finger pointing
2) Check your oil level regularly. If you notice it’s low, check for signs of leakage on your garage floor or driveway. If you find leakage, check drain plug tightness yourself or take it to the shop that did the work.

Don’t allow yourself to be caught in the middle between the oil change facility and Hyundai or Kia. Always check your oil.

©, 2022 Rick Muscoplat