2017 Hyundai Sonata: Engine complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 400 owner complaints for the 2017 Hyundai Sonata that list the engine component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11771429 (filed 10/15/2026): “I had recently taken my 2017 hyundai sonata in for an engine diagnostic check at the bel air hyundai dealership, (10/15/26) worth $199.99 for an hour of maintenance, after experiencing sudden jolts when powering on and driving, needing additional time warming up. my initial thought was that the temp…”
- NHTSA complaint ODI #11766104 (filed 09/22/2026): “I am reporting an unaddressed, critical safety defect involving the theta ii engine in my 2017 hyundai sonata. the engine has developed a severe internal metallic knocking noise consistent with connecting rod bearing failure—the exact manufacturing defect associated with hyundai's major engine recal…”
- NHTSA complaint ODI #11762255 (filed 09/04/2026): “The vehicle suffered a sudden, catastrophic internal mechanical engine failure out of nowhere without any warning lights or previous symptoms. an inspection of the engine cylinder revealed a physical hole blown through the top of the cylinder 2 piston, causing immediate and complete loss of engine c…”
Likely causes
These complaints do not establish a single root cause; read the examples above and get a diagnosis.
Fix, in plain English
No single fix is established by these reports. Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer about technical service bulletins (TSBs) or extended warranty coverage, then have the system diagnosed.
DIY difficulty: Pro
Internal engine work (lifters, oil consumption, fuel dilution diagnosis) requires engine teardown or dealer software/tests. (Our assessment.)
Cost
No sourced cost range for this issue. Get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
AutoZone · O'Reilly · Advance · RockAuto
Sources
Page last updated .