Problems · by component

2018 Hyundai Sonata engine problems

212 owner complaints to NHTSA about the 2018 Hyundai Sonata cite engine, 57% of all 375 complaints for this model year.

Complaints
212
57% of all complaints
Crashes
3
Reported by owners
Fires
8
Reported by owners
Injuries
2
Reported by owners
01 —Owner reports

What owners say about the engine

Verbatim from NHTSA complaints, newest first
“What component or system failed or malfunctioned, and is it available for inspection upon request? The paint is peeling off the car, when I went to the dealership they said this is a known problem for 2015-2018, but they can't fix it there is no recall. It is causing rust. The valve cover gasket leaks oil and caused spark plugs to blow twice. How was your safety or the safety of others put at risk? The valve cover has caused my wife to be stuck on the side of the road early morning and my child to break down in another state. Has the problem been reproduced or confirmed by a dealer or independent service center? The dealer stated both of these are known issues for these years, 2015-2018. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? We took the car into the dealership for inspection. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There was no warnings for either item.”
Owner complaint to NHTSAFiled Oct 5, 2026Structure, EngineODI 11769166
“Hyundai dealership confirms I am in need of a new engine due to large oil consumption which is a known issue on 2018 Hyundai Sonata engines. Hyundai will not approve repairs because I am the second owner and vehicle is out of the 5 year warranty period. I only have 52K miles on my vehicle.”
Owner complaint to NHTSAFiled Sep 21, 2026EngineODI 11765780
“Since I had Service Campaign 9C2 completed, the car hesitates to start, does a mini-lurch upon cold start and runs rough. Two weeks ago, it was put in park, lurched backwards, then died. The starter and battery have been replaced but this has not helped. The car ran fine before this update was done.”
Owner complaint to NHTSAFiled Aug 25, 2026EngineODI 11759477
“I recently had the 9C2 Emissions recall update performed on my car, and since the update my car drives like total garbage after a cold start. It hesitates to accelerate, it bucks when trying to accelerate, and it’s to the point the engine is about to stall. I took it back to the Hyundai dealership and they said they are aware of the issue, but there is no fix from Hyundai at this time. This is a major safety concern, as the car barely wants to accelerate after a cold start. Please have Hyundai fix this safety issue.”
Owner complaint to NHTSAFiled Aug 16, 2026Power train, EngineODI 11757253
“The paint on all parts of the car is completely coming off down to bare metal. It’s as if the car wasn’t prepped to receive paint. Every Hyundai I pass that’s white the paint is coming off. There is also an internal engine oil leak where I’m losing 4qts of oil a week.”
Owner complaint to NHTSAFiled Aug 16, 2026Structure, EngineODI 11757263
“The lower aluminum engine oil pan developed a structural hairline fracture ("micro-crack") directly along the factory casting ridge adjacent to the drain plug. The component failed without any external impact, road hazard, scraping, or underbody damage. The failure was officially confirmed and documented by Eckert Hyundai during a service visit on July 13, 2026 (Case #42971835). Following the dealer oil service, the fracture degraded into an active, worsening oil drip that requires a catch tray under the vehicle to capture leaking fluid. The vehicle is currently available for inspection. Safety Risk: An active engine oil leak poses a significant safety hazard. Rapid or continuous loss of engine oil can cause sudden oil starvation, severe engine seizure, or total power loss without warning while driving at highway speeds, increasing the risk of a crash. Furthermore, dripping oil contacting hot exhaust or engine components presents a potential fire hazard. Prior Symptoms / History: This vehicle has a well-documented history of severe internal engine issues and thermal stress, including excessive oil consumption (running 1.2 quarts low in 1,127 miles), valve cover…”
Owner complaint to NHTSAFiled Jul 20, 2026EngineODI 11751641

Showing 6 of 212 reports. Read every report on NHTSA.gov.

Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 9, 2026NHTSA vehicle page

Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.