Diagsheet

2018 Hyundai Sonata · symptom sheet

Engine failure, knocking or rod bearing

  • 87owner reports
  • 22,000median miles
  • $564median quote
  • 1involved a crash

Newest report Jul 20, 2026 · checked Sep 9, 2026

221 of the 370 complaints on this car are about the engine. 87 of those describe engine failure, which makes it the most reported problem on the 2018 Sonata.

Tick what matches of 87 reports

37
15
14
18
27
18

What got replaced

Owners who name the part that was replaced mention the engine (83 reports).

Recalls and investigations

No recall on the engine covers the 2018 model year as of Sep 9, 2026.

NHTSA investigations into the engine on the Sonata

DP22-003opened Sep 12, 2022
Engine · model years 2006 to 2021

Loss of motive power. Closed dec 12, 2023.

NHTSA summary
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experiencing rapid loss of engine oil due to oil drain plug back outs, resulting in loss of motive power and/or catastrophic engine damage. Additional complaints were provided which alleged that the oil drain pans lack sufficient structural integrity and are susceptible to cracking. The petition itself can be reviewed at NHTSA.gov under ODI number 11481745. On September 12, 2022, the Office of Defects Investigation (ODI) opened Defect Petition (DP22-003) to evaluate the Petitioners’ request. The Petitioners have provided additional complaints within four supplemental letters dated January 31, 2023, March 21, 2023, May 23, 2023, and August 4, 2023. ODI’s evaluation included the review and analysis of the complaints and supporting information submitted by the Petitioners, as well as additional complaints submitted directly to NHTSA which referenced either the oil drain plug or a crack in the oil pan. After reviewing the available data, ODI has not identified evidence that would support opening a defect investigation into the oil drain pan as
EA21-003opened Dec 22, 2021
Engine · model years 2011 to 2016

Engine fires. Closed feb 5, 2024, led to recall 23V-877.

NHTSA summary
On March 29, 2019, the Office of Defects Investigation (ODI) opened two Preliminary Evaluations (PE19-003 on Hyundai and PE19-004 on Kia) to broadly investigate incidents of non-crash fires (regardless of origin or operational status of the vehicle) on various model year Hyundai and Kia vehicles. During the PE investigations, Hyundai and Kia issued several recalls to address vehicle fires, including those due to engine failures involving various engine types. The remedies for the engine failure recalls typically involve engine inspection (to detect existing damage), and if necessary, engine replacement. Additionally, both manufacturers have been installing an engine control software modification known as Knock Sensor Detection Software (KSDS) which is intended to detect impending engine failure, alert the driver, and limit engine power (to lessen likelihood of engine failure).KSDS is being installed under recalls and non-safety field actions, and both companies have extended limited engine warranties (see recall files). On December 22, 2021, ODI upgraded PE19-003 and PE19-004 to this Engineering Analysis (EA21-003, covering both Hyundai and Kia) to evaluate the scope of the prior recalls related to engine failures/fires and the efficacy of the recall remedies for the recalls, as well as the long-term viability of related programs and non-safety field actions being conducted by Hyundai and Kia. The former issue involved approximately 550,000 MY 2013 Hyundai Elantra, MY
RQ17-004opened May 18, 2017
Engine · model years 2011 to 2014

Scope and timeliness. Closed dec 22, 2021, led to recall 17V-226.

NHTSA summary
NHTSA opened Recall Query (RQ) 17-004 to investigate the timeliness and scope of Hyundai?s Theta II GDI engine recalls (Recall Nos. 15V-568 and 17V-226), and Hyundai?s compliance with reporting requirements. On November 23, 2020, the Agency entered into a Consent Order with Hyundai to administratively resolve NHTSA?s assertions of violations of law in connection with RQ17-004. NHTSA?s assertions included that Hyundai may be liable for civil penalties on multiple grounds, including the untimeliness of Recall Nos. 15V-568 and 17V-226, inaccuracies in Hyundai?s recall reports, and that a required report describing potential safety-related issues contained certain inaccuracies or omissions.Under the Consent Order, Hyundai agreed to a total civil penalty of $140,000,000. The total civil penalty included payment of $54,000,000 as a Non-Deferred Amount. Hyundai also agreed to a sum of $46,000,000 as an Abeyance Amount to be deferred and held in abeyance pending its satisfactory completion, as reasonably determined by NHTSA, of the requirements of the Consent Order.Additionally, Hyundai agreed to a $40,000,000 Performance Obligation Amount to be expended by Hyundai to fulfill specified Safety Data Analytics Infrastructure obligations and Test and Inspection Laboratory obligations. The Consent Order also includes other terms designed to enhance Hyundai?s safety practices, and requires Hyundai to retain a Third-Party Auditor who directly reports to NHTSA.Other than RQ17-004, the Consen

What owners paid

13 of the 87 reports quote a price. Each dot is one quote. The middle half runs $350 to $850.

$350$564$850
$0k$2k$4k$6k$8k

When it happens

The middle half of failures fell between 3,000 and 86,500 miles, from the 54 reports that gave a mileage.

1619
220
221
422
1423
1524
2125
1326

What owners wrote

“Engine failure. Definitely a safety issue, check engine light flashing, limited engine power. Wouldn’t accelerate. Dealer inspected, there is a nationwide recall and class action lawsuits and they won’t replace even though it’s under warranty. False information saying maintenance neglect on my part. That is FALSE. Known failure and oil consumption. Rod bearing failure.”

Filed Aug 11, 2025

“2018 Hyundai Sonata with only 128k miles already needs a new engine due to oil consumption. I have done the regular maintenance on the car and have only put roughly 25k miles on the car since owning it”

Filed Jan 16, 2025 · 128,000 miles

“Car has an engine defect and consumes too much oil. Hyundai Sonata is denying the repair or engine replacement”

Filed Sep 27, 2024

“Had issues with engine consuming oil. Took to dealer who completed an engine oil consumption test to find the engine oil was 3 quarts low. All services had been completed through the dealer for the life of the vehicle. Engine replacement was approved. Vehicle was still under warranty. Vehicle was at 88227 miles when taken to dealer for repairs for oil consumption.”

Filed May 16, 2024 · 88,227 miles

Should you keep driving it?

This page can't tell you that. 1 of 87 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.

File your own report with NHTSA. Complaint counts are how a problem gets an investigation.

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