About this problem
Engine failure complaints describe engines that knock, seize or stop running entirely, often with a sudden loss of power on the road. The usual mechanical cause is wear in the connecting rod bearings, which can follow from manufacturing debris, low oil or oil starvation. Once a bearing fails, the engine usually needs to be replaced. Some failures on these engines are covered by recalls or extended warranties.
Across all owner complaints filed about the Hyundai Sonata since 2012, 1,685 (19.3%) describe engine knocking and failure, making it the most reported problem we track on the Sonata. The reports cluster on the 2012, 2013 and 2015 model years, and the 2013 drew the most, with 413. It tends to show up at higher mileage: half of the owners who gave a mileage were between 66,000 and 123,000 miles. 84 reports describe a crash or fire linked to it. 5 recalls are related to it, and recall repairs are free at any dealer.
What owners report
Owners of 2011 to 2015 Sonatas report knocking, stalling, loss of power and engines that seized, sometimes with fires. These are among the most recalled engines of the decade, and Hyundai extended engine warranties on many cars. The 2012 and 2013 cars drew the most reports.
How it gets fixed
Hyundai replaces failed engines under recalls 15V568, 17V226 and 18V934 or the warranty extension, after a knock sensor software update.
Typical cost: Free if covered. Otherwise a replacement engine costs $4,000 to $7,000.
Complaints by model year
In owners' words
"Without notice/warning, engine started making a metallic knocking/flapping sound with a lot of blue smoke exhaust when rapidly accelerating. Shortly after, engine oil light flickered momentarily. From past experience, I knew to pay attention to this."
2012 Hyundai Sonata, 39,250 miles
"At 1540 miles 2015 Hyundai Sonata limited engine cam advance sensor failed. This caused engine running rough and limited power with inability to climb hills without constantly downshifting."
2015 Hyundai Sonata, 1,540 miles
"A knocking sound could be heard under the hood as I started my car up. I took it to the maintenance mechanic immediately, and was informed the engine was going bad. I was instructed to drive it to the nearest Hyundai dealership, which is 4 miles away."
2013 Hyundai Sonata, 63,223 miles
Excerpts from public owner complaints filed with the National Highway Traffic Safety Administration, lightly trimmed.
Related recalls
Hyundai Motor America (Hyundai) is recalling certain 2011-2014 Sonata and 2013-2014 Santa Fe Sport vehicles previously repaired under recall numbers 15V-568 and 17V-226.
Hyundai Motor America (Hyundai) is recalling certain model year 2011-2012 Sonata vehicles manufactured December 11, 2009, to April 12, 2012 at Hyundai Motor Manufacturing Alabama and equipped with either a 2.0 liter or 2.4 liter Gasoline Direct injection engine.
Hyundai Motor America (Hyundai) is recalling certain 2015-2016 Veloster, 2012 Santa Fe, 2011-2013 Sonata Hybrid, and 2016 Sonata Hybrid vehicles.
Hyundai Motor America (Hyundai) is recalling certain 2013-2014 Sonata and Santa Fe Sport vehicles.
Hyundai Motor America (Hyundai) is recalling certain 2017 Tucson and Sonata Hybrid vehicles.
Recall repairs are free at any dealer. Check a specific car by VIN at nhtsa.gov/recalls.
Service bulletins and warranty extensions
Hyundai has sent dealers 31 bulletins that mention this problem on the Sonata. A bulletin tells technicians how to fix a known fault. It is not a recall, so the repair is usually free only while the car is under warranty or covered by an extension.
Hyundai has developed a new engine monitoring technology called a Knock Sensor Detection System (KSDS).
The warranty coverage for engine repair or replacement regarding engine damage or malfunction from connecting rod bearing wear has been extended to 15 years or 150,000 miles from the date of original retail delivery or date of ...
Hyundai is providing extended warranty coverage to both new and used vehicle owners for engine long block assembly repairs needed due to excessive connecting rod bearing damage upon completion of Service Campaign 953.
Hyundai is providing an extended warranty for the engine short block assembly (consisting of the engine block, crankshaft and bearings, connecting rods and bearings, and pistons) on 20112014 sonatas.
This bulletin provides warranty extension information regarding the engine short block assembly (consisting of the engine block, crankshaft and bearings, connecting rods and bearings, and pistons) on 2011-2014my Sonata (yf) veh...
Follow the guidelines outlined in this bulletin to inspect and clean or replace certain components of the engine intake system accordingly during engine short block or sub-assembly replacement.
Government investigations
Defect petition DP18003 · 2012–2014 · opened Aug 2018, closed May 2019
Engineering analysis EA21003 · 2012–2017 · opened Dec 2021, closed Feb 2024
Preliminary evaluation PE19003 · 2012–2014 · opened Mar 2019, closed Dec 2021
Before you buy a Sonata
- Ask for oil change records; long gaps are a red flag on these engines.
- Listen for knocking or ticking at idle and when accelerating.
- Check by VIN for open engine recalls and for any extended engine warranty.
Questions
Which Hyundai Sonata years have engine knocking and failure?
Complaints are highest for the 2012, 2013, 2015 model years. The 2013 drew the most, with 413 reports.
At what mileage does it usually start?
Among owners who gave a mileage, the middle figure was about 93,000 miles, and half reported it between 66,000 and 123,000 miles.
How much does it cost to fix?
Free if covered. Otherwise a replacement engine costs $4,000 to $7,000.