2021 Kia Seltos engine problems

Owners report their 2021 Seltos burning through oil at rates far exceeding normal (often 1+ quart per 1,000 miles or worse), with no external leaks visible. Root cause alleged to be defectively heat-treated piston oil rings per Kia recalls SC209 (21V-259) and SC336 (25V-099). This results in cylinder wall scoring and progressive internal damage.

When: Typically begins 10,000–30,000 miles; some owners don't discover the issue until much higher mileage. Two narratives mention discovery during recall-related maintenance attempts.

Symptoms owners cite: Rapid oil level drop between scheduled oil changes (sometimes 1–4 quarts in 1,000–5,000 miles); No visible oil leaks underneath vehicle; Burning oil smell or white smoke from exhaust in some cases; Engine knocking, rattling, or ticking noise during idle or acceleration

Codes mentioned: P0011 (Intake cam timing over-advanced), P0301 (Cylinder 1 misfire), P0304 (Cylinder 4 misfire), P1327 (PNSS-detected knock), P0017 (Crankshaft/camshaft correlation error), P1327, P0304, P0017 (stored in history, sometimes not active when retested)

Repairs/costs cited: Combustion chamber cleaning (~$1,000 reported in one case); PCV valve replacement (~$1,000 in one case). Many owners report Kia requires multi-round oil consumption tests (1,000 miles per round, up to 3 rounds) before authorizing engine work. Final remedy stated in recalls to be full long-block engine replacement, but dealerships often refuse or delay based on 'test failure' criteria or warranty exclusions. Out-of-pocket engine replacements have cost owners $1,300–$6,700+.

Recalls/TSBs owners mention: Kia recalls SC209 (21V-259, July 2021 launch) and SC336 (25V-099, April 2025 launch). SC209 involved piston-ring noise sensing system (PNSS) software install and vibration testing; owners allege it did not replace rings or prevent recurrence. SC336 promised full engine replacement if defect confirmed, but rollout halted in May 2025 due to 'too many engines failing.' Dealers cite various reasons for denial: vehicle out of warranty, second owner, insufficient maintenance records, code cleared before retest, vehicle not on official recall VIN list, or 'passing' oil consumption test. TSB ENG222 Rev 6 mentioned by one owner for stalling issues but repair was denied due to ownership transfer and warranty expiration.

Owners report sudden engine stalling or loss of acceleration while driving at various speeds—some at idle or stop lights, others at highway speeds (45–70 mph). No warning lights in many cases prior to or during the event. Vehicle becomes undriveable and requires towing.

When: Occurs across wide mileage range: 19,000–110,000 miles. Some cases happen shortly after recall repair attempt; others happen months or years after purchase.

Symptoms owners cite: Sudden stall at idle, stop light, or during acceleration; Loss of power or failure to accelerate when pedal pressed; Engine shuddering or vibrating before stall; No warning lights in many cases; check-engine light only illuminates after stall in some; Vehicle difficult or impossible to restart; Flashing check-engine light in some cases

Codes mentioned: P0011 (Intake cam timing), P1327 (Piston noise detection), P0132 (Piston Noise Detection, system too lean), P0171 (System Too Lean – Bank 1)

Repairs/costs cited: Many vehicles diagnosed as having seized or locked engines requiring replacement. One owner paid $250 diagnostic fee plus additional $500 diagnostic fee; another paid $1,304.91 out of pocket with partial goodwill assistance. Dealers often only perform oil changes and code clearing rather than addressing root cause. Some owners report dealerships refusing to diagnose or work on vehicle until diagnostic fees are paid.

Recalls/TSBs owners mention: Kia's recall (SC336/25V-099) and prior SC209 (21V-259) intended to address this via software update and full engine replacement if defect confirmed. However, several owners report dealerships halting or reversing recall repair based on test results or claim the vehicle 'passed' a retest even after stall incident. One owner reports Kia told dealership 'they are taking the side of the dealership' when code was cleared before full engine replacement could be authorized. Post-recall failures documented in multiple narratives.

Owners report engines that suddenly seize or lock up during or after driving, with no oil present or severely low oil. In some cases, loud clanking or knocking precedes seizure; in others, seizure happens without warning. Vehicle cannot be restarted.

When: Reported between 38,000–110,000 miles. One case occurred 4 times over one year, each time requiring towing.

Symptoms owners cite: Loud clanking or rattling noise from engine before seizure; White smoke or burning smell from engine compartment; Engine will not turn over or crank; No compression in one or more cylinders (e.g., 135 psi in cylinder 1, 105 psi in cylinder 3, both with excessive scoring); Excessive cylinder wall scoring visible on inspection

Codes mentioned: P0011 (Intake timing), Engine locked up (non-code diagnosis, compression test failure)

Repairs/costs cited: Requires full engine replacement. One owner paid $1,304.91 out of pocket after Kia refused full coverage (dealership only authorized partial goodwill). Another had engine seized at 71,728 miles with 3 quarts low oil; dealership cleared codes and declared car 'good to go' without replacing engine, leading to second failure. Repair costs not disclosed in many cases, but several owners indicate lengthy delays and refusals to perform work.

Recalls/TSBs owners mention: Kia recalls SC209 and SC336 intended to prevent seizure via early detection and engine replacement. However, multiple narratives document seizure occurring after recall work was performed or claimed to be completed. One owner reports dealership states 'engine does not qualify for replacement under the recall for not meeting the workflow criteria.' Another reports vehicle was repossessed because Kia/dealership refused to repair. Insurance or lease company involvement noted in some cases.

Kia issued multiple recalls for piston oil ring defects (SC209/21V-259 in July 2021; SC336/25V-099 in April 2025), but owners report extensive delays, cancelled appointments, process restarts, and outright refusal to perform recalls. In May 2025, SC336 rollout was halted due to 'too many engines failing.' Dealers cite missing parts, unclear procedures, coolant temperature requirements, and code-clearing as reasons to defer or avoid completion.

When: Begins April–May 2025 for SC336; ongoing into 2026. One owner's SC209 repair (July 2021) failed to fix the defect; owner later denied SC336 coverage due to being 'second owner.'

Symptoms owners cite: Appointment cancelled without clear explanation; Dealership states 'recall is on hold' or 'parts not available'; Dealership postpones or refuses recall service even after owner schedules; Excessive wait times (one owner waited ~1 month with no ETA; another had car for 2+ weeks); Dealership performs incomplete work (e.g., 'retest' only, no parts replaced) then claims car 'passed'; Dealership cites technical requirements (e.g., 'coolant temperature too low' at 82°F) to refuse service

Repairs/costs cited: No repairs completed in many narratives. When work was done, often only software updates (PNSS/vibration sensing) or oil changes performed, not full engine replacement as promised. One owner reports dealership kept car for 1 month saying engine replacement needed, then only did a 'retest' and passed it without explanation. Another owner reports dealership refused to re-test after owner sought second opinion.

Recalls/TSBs owners mention: Kia corporate acknowledged SC336 recall (25V-099) and promised engine replacement at no cost if defect confirmed. However, narratives indicate corporate also cited 'halt' in process to fix inspection procedure (May 2025), denied repeated owner calls for updates, told customers 'parts unavailable,' or stated recall could not be performed due to 'workflow criteria' or vehicle not meeting recall VIN range. One owner states Kia corporate told them 'we are taking the side of the dealership' when code was cleared.

Dealers and Kia corporate frequently deny repair authorization or warranty coverage citing reasons such as: missing maintenance records (even when owner provides proof), second ownership, powertrain warranty expiration, code already cleared by previous repair attempt, vehicle 'out of recall VIN range' despite having identical engine/model year, or claim that oil consumption is 'normal.'

When: Happens at point of repair request, typically after owner discovers issue or attempts to use recall.

Symptoms owners cite: Dealership refuses to work on vehicle without proof of oil changes; Corporate/dealership claims vehicle not on official recall list despite matching defect description; Warranty voided due to 'late oil changes' (e.g., one owner within 1 oil change of maintenance interval); Denial based on second-owner status or ownership transfer; Dealer claims 'oil consumption test passed' (e.g., 0.77 quarts per 1,000 miles acceptable) despite obvious engine damage

Repairs/costs cited: Out-of-pocket repair costs range from $1,300–$6,700+ when owners forced to pursue independent engine replacement. One owner charged $250 diagnostic, then additional $500 when engine already confirmed locked. Another owner quoted $6,679.15 for long-block replacement after being told warranty voided.

Recalls/TSBs owners mention: Kia corporate cites warranty limitations, maintenance record gaps, and ownership transfer as grounds for denial. However, multiple narratives show Kia promised engine replacement 'at no cost' in recall literature, then reversed decision at point of service. One owner reports being told goodwill approval was rescinded and removed from system. Another reports Kia corporate refusing to escalate or follow up despite filed case number.

Owners report that after Kia dealership completed recall work (often SC209 software update and vibration testing, or SC336 inspection), the vehicle subsequently exhibited worsening symptoms—excessive oil consumption, engine stalling, knocking—leading to engine seizure or failure requiring replacement.

When: Days to weeks after recall repair completion; one owner noticed issues 'immediately after' driving off dealer lot.

Symptoms owners cite: Engine light illuminates after previously passing recall test; Increased knocking, rattling, or ticking noise; Vehicle stalls or loses power after passing 'inspection'; Oil level drops more rapidly after repair; Check-engine light flashing or intermittently on with stored/history codes

Codes mentioned: P0011 (returned after clearing), P1327 (returned after clearing)

Repairs/costs cited: Dealerships often refuse warranty service for post-recall failures, claiming 'recall is not responsible for this' or vehicle was already damaged. Owners forced to pay out of pocket or escalate to Kia corporate. One owner reports dealership charged $100+ diagnostic fee after recall work made symptoms worse.

Recalls/TSBs owners mention: Kia corporate and dealers deny accountability, asserting recall work was 'completed per Kia instructions' or 'software update was the fix.' However, NHTSA audit noted (per one narrative) 'ineffective fixes, with owner complaints of post-repair failures.' Owners frustrated by lack of accountability for failed recall repairs.

Multiple owners report that during SC209 recall (2021), dealers performed only piston-ring noise sensing system (PNSS) software install and vibration testing, but did NOT replace the defective piston rings themselves. Owners allege defective rings remained in engine, leading to continued or recurrent failures.

When: SC209 performed July 2021–early 2022. One owner discovered non-completion when requesting documentation; another discovered because symptoms persisted.

Symptoms owners cite: Dealer notes indicate 'Piston Ring Inspection performed' but no parts replaced; Software/program update installed instead of hardware replacement; Symptoms (knocking, stalling, oil loss) return or continue after recall completed; Owner told by dealer/Kia that software 'detects' knock but does not 'fix' underlying ring defect

Repairs/costs cited: No actual parts replaced; only software deployed. One owner explicitly states: 'My vehicle was not repaired. A vibration test was done and a program update was installed to detect vibration. The vehicle still has the recalled damaged oil rings.'

Recalls/TSBs owners mention: Kia's SC209 recall was designed to update vibration sensing logic to catch early signs of ring failure, but not to replace rings. This prompted the subsequent SC336 recall (2025) with full engine replacement as remedy. However, owners claim the two-step approach left them in unsafe vehicles for years and caused continued damage.