Over the last decade, Hyundai has earned both praise and criticism—praise for its sleek designs and competitive pricing, and criticism for persistent engine problems that plagued a wide range of models. But have these problems been resolved, or are drivers still rolling the dice under the hood? For years, Hyundai struggled with a series of serious engine defects. The most well-known issues included excessive oil consumption, knocking sounds, engine stalling, and in some cases, fire risk. These problems were traced back to design and manufacturing flaws in engines like the 2.0L Nu MPI and the Theta II—popular powerplants found in models like the Elantra, Kona, and Veloster. The trouble stemmed from defective piston rings and faulty heat treatment during the production process. This led to premature wear and tear, reduced engine performance, and potential safety hazards. Some engines were also affected by connecting-rod bearing failure, which could cause the engine to seize or, in worst cases, catch fire.
Hyundai didn’t ignore the complaints. Over the years, the automaker issued multiple recalls to address these engine defects. Many of the affected vehicles were brought in for free inspections and software updates designed to detect early signs of piston damage. In many cases, owners received entirely new engine replacements, at no cost. The company also extended its powertrain warranties for many affected vehicles to 15 years or 150,000 miles, offering added peace of mind to those still behind the wheel of older models. More recently, Hyundai updated its engine designs, especially after 2020, incorporating new piston coatings, better valve seals, and improved crankcase ventilation systems.
Starting around mid-2020, Hyundai began rolling out its newer Smartstream engines. These powertrains feature updated engineering that directly addresses the issues found in earlier designs. From revised piston rings to better oil control and improved durability, these newer engines are showing far fewer complaints among drivers. While long-term reliability data is still developing, early signs indicate that Hyundai’s updated engines are performing much better. Models equipped with the 1.6L and 2.5L Smartstream engines, for instance, are reportedly more efficient and less prone to the oil-burning and knocking problems that plagued earlier designs.
If you’re driving or considering buying a Hyundai manufactured before 2020—especially one with a 2.0L Nu MPI or Theta II engine—you’ll want to proceed with caution. Not all vehicles have been repaired, and some owners report continued oil consumption or engine noise even after software updates. The good news? Many of these vehicles are covered under Hyundai’s extended engine warranty, and class-action settlements have helped provide financial relief for major repairs. If your car hasn’t been inspected yet, it’s worth checking your VIN for any open recalls or service campaigns.
Hyundai has clearly put serious effort into correcting its past mistakes. The newer models, especially those built after 2020, show noticeable improvements in both design and reliability. However, older engines still carry some baggage—and unless they’ve been repaired or replaced, lingering issues may remain. For potential buyers, the advice is simple: newer is better. If you’re already driving a Hyundai from the affected years, take full advantage of any warranty coverage and stay on top of oil levels and service alerts.
🔍 What you can do:
1. Check your VIN via NHTSA or Hyundai official site for open recalls.
2. Ask your dealer if your engine was produced before—or updated after—mid‐2020. Also ask whether your engine has the redesigned piston rings, updated PCV, etc.
3. Use the extended warranty: If you're covered, even older models may qualify for free engine repair or replacement under the class‐action settlement.
4. Watch for warning signs: frequent oil loss, knocking, flashing oil light, or sluggish performance warrant prompt service.
