2021 Hyundai Sonata Engine Problems

NHTSA component category: ENGINE · data through 09/08/2026

34Engine complaints

26.2%Of all 130 complaints

#1Most-reported category

Source: U.S. NHTSA complaint data. Complaints are unverified reports from vehicle owners — a complaint is not a confirmed defect.

How engine ranks on this vehicle

ENGINE34 · 26.2%

Unspecified / other32 · 24.6%

POWER TRAIN22 · 16.9%

FUEL/PROPULSION SYSTEM20 · 15.4%

ELECTRICAL SYSTEM16 · 12.3%

Share of the 130 complaints citing each category; one complaint can cite several. Full breakdown on the 2021 Hyundai Sonata overview page.

What owners report

“The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the engine shuddered and the engine stalled. In addition…”NHTSA complaint 11738864 — filed 05/19/2026

“The Exhaust Heat Recovery System (EHRS) has failed for the second time on this vehicle. The first failure occurred at approximately 35,000 miles and was…”NHTSA complaint 11730992 — filed 04/14/2026

“Vehicle suddenly lost heat in 30 degree weather. No warnings, check engine light, or temperature gauge indicators came on. Lucky made it to a parts…”NHTSA complaint 11718194 — filed 02/16/2026

Excerpts are shortened and scrubbed of personal details; they are individual, unverified reports.

Engine complaints by year filed

Frequently asked questions

Does the 2021 Hyundai Sonata have engine problems?

Engine is the most-reported problem area on the 2021 Hyundai Sonata: 34 of 130 complaints on file (26.2%). Complaints are unverified owner reports, not confirmed defects.

How many complaints does the 2021 Hyundai Sonata have in total?

130 complaints were on file with NHTSA as of 09/08/2026. Across all categories, 7 involved a crash, 0 involved a fire, 12 reported injuries, and none reported deaths.

What does NHTSA's engine category include?

NHTSA assigns each complaint to standard component categories; this page reports the ENGINE category exactly as NHTSA defines and records it.

About this data — Complaint figures on this page are consumer reports submitted to the National Highway Traffic Safety Administration (NHTSA), a U.S. government agency. NHTSA does not verify individual complaints; a complaint is not proof that a defect exists, and counts reflect what owners chose to report, not confirmed failure rates. Recall information comes from official NHTSA safety recall campaigns; recall repairs are free at authorized dealers. Always check your specific vehicle by VIN at nhtsa.gov/recalls. CarModelProblems.com is an independent site and is not affiliated with NHTSA or any vehicle manufacturer. Data through 09/08/2026.