2020 Kia Cadenza Problems: 3 Issues Every Owner Should Know

2020 model year · 240+ owner reports · Updated May 2026

According to Au7o's analysis of 240+ owner reports, the 2020 Kia Cadenza has 3 documented known issues, with 2 rated critical. The most serious are 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure ($0-$6,000 repair) and Panoramic Sunroof Glass Spontaneous Shattering ($800-$1,500 repair). The most commonly reported issue is 6-Speed Automatic Transmission Hesitation and Hard Downshift with 110 owner reports. Across all issues, repair costs range from $800 to $6,000. DIY maintenance guides at au7o.io.

All 3 Known Issues

Community Reported

75 owners

On the 2014-2020 Kia Cadenza 3.3L Lambda II GDI V6, the Cadenza's 3.3L Lambda II GDI V6 is covered under the Hyundai/Kia engine settlement for connecting rod bearing failure. Manufacturing debris in the crankshaft oil passages can restrict oil flow to the connecting rod bearings, causing premature wear and eventual engine seizure. Kia extended the engine warranty to 15 years/150,000 miles. The issue typically manifests as a knocking noise from the bottom end of the engine, often preceded by an illuminated oil pressure warning light.

This issue also affects: Buick LeSabre, Buick Park Avenue, Buick Encore

Common Symptoms

Knocking noise from lower engine that increases with RPM
Low oil pressure warning light
Check engine light illuminated
Metal particles visible in oil during oil change
Engine stalling or seizing

How to Fix

Contact a Kia dealer immediately for inspection under the extended warranty (15 years/150,000 miles). Kia performs a rod bearing clearance test and inspection. If the bearings are worn, Kia replaces the engine at no cost with a remanufactured unit. Keep all oil change records as proof of maintenance — they are required for warranty claims.

What Owners Are Using

Parts and tips from 75+ owners who fixed this issue

TipCheck with Kia dealer about the 15 year/150,000 mile extended engine warranty — engine replacement is free for covered vehicles
TipKeep ALL oil change receipts in the glove box — Kia requires proof of regular oil changes for warranty engine replacement
NoteStop driving immediately if you hear knocking — continued driving can cause the rod to punch through the engine block, voiding warranty coverage
UpgradePerformance engine bearing set for reliable bottom-end protection (ACL Engine Bearing Set)
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UpgradeAssembly lube protects bearings during initial startup after rebuild (Permatex Engine Assembly Lube)
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Typical repair cost:$0 - $6,000

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75+ owners have reported this issue

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Community Reported

Low Confidence75 reportsLast reported by owners Mar 2026Reviewed Mar 2026

Community Reported

55 owners

On the 2014-2020 Kia Cadenza, the Cadenza equipped with the panoramic sunroof has experienced instances of the tempered glass panel spontaneously shattering without external impact. The glass explodes with a loud pop, showering the interior with small tempered glass fragments. This appears to be caused by stress fractures in the tempered glass from manufacturing defects or frame flex. While tempered glass shatters into small pebble-like pieces rather than sharp shards, the event is extremely startling and leaves the vehicle open to weather.

Common Symptoms

Loud pop or explosion sound from roof
Sunroof glass shattered with no external impact
Small glass fragments throughout interior
Wind noise and water intrusion through broken glass
Glass shattering while parked (thermal stress)

How to Fix

Cover the opening immediately with plastic sheeting and tape if the glass shatters. File a claim with Kia — some owners have received goodwill coverage for replacement even outside warranty due to the spontaneous nature of the failure. The replacement glass panel from Kia dealer is $800-1,200 installed. Aftermarket sunroof glass is not available for the Cadenza. File a complaint with NHTSA to support potential recall investigation.

What Owners Are Using

Parts and tips from 55+ owners who fixed this issue

TipContact Kia corporate (1-800-333-4542) for goodwill coverage — many owners have received free or reduced-cost replacement due to the spontaneous nature
TipFile a complaint with NHTSA at safercar.gov — documented complaints increase the likelihood of a recall investigation
NoteKeep a roll of plastic sheeting and duct tape in the trunk — if the glass shatters, you need to weather-proof the opening immediately to prevent interior water damage
UpgradeTrim removal tool set for body panel work without damage (MICTUNING Trim Removal Tool Set)
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UpgradeBondo body filler for dent and panel repair (Bondo Body Filler Kit)
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Typical repair cost:$800 - $1,500

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55+ owners have reported this issue

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Community Reported

Low Confidence55 reportsLast reported by owners Mar 2026Reviewed Mar 2026

Community Reported

110 owners

On the 2014-2020 Kia Cadenza, the Cadenza's 6-speed automatic transmission (A6LF2) exhibits a hesitation or delayed response when accelerating from low speeds, particularly after coasting to a stop. The transmission seems to "hunt" for the right gear, causing a 1-2 second delay before power delivery. Hard downshifts also occur during passing maneuvers. Kia released multiple TCM software updates to address the shift calibration but many owners report the issue persists.

This issue also affects: Acura TL, Acura CL, Acura ILX

Common Symptoms

Hesitation or delay when accelerating from a stop
Hard downshift when passing on the highway
Transmission "hunting" between 2nd and 3rd gear at low speed
Jolt or jerk during 1-2 upshift
Delayed throttle response when merging

How to Fix

Visit a Kia dealer for the latest TCM software update — multiple updates have been released through 2020. A complete transmission fluid drain and fill with Kia SP-IV ATF can improve shift quality. If the problem persists after the software update, the valve body may need replacement. Some owners report improved behavior after an "adaptive learn" reset performed with the KDS scan tool.

What Owners Are Using

Parts and tips from 110+ owners who fixed this issue

TipAsk the dealer to check for the latest TCM software update — Kia has released several recalibrations that specifically address the hesitation issue
TipA complete ATF drain and fill with genuine Kia SP-IV fluid often improves shift quality — change every 30,000 miles
NoteDo not use aftermarket ATF — the A6LF2 is calibrated specifically for SP-IV viscosity and friction characteristics
UpgradeReplacement shift solenoid to restore proper gear engagement (Dorman Transmission Shift Solenoid)
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UpgradeTransmission filter kit with gasket for fluid service after solenoid replacement (ATP Transmission Filter Kit)
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Typical repair cost:$0 - $2,000

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110+ owners have reported this issue

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Community Reported

Low Confidence110 reportsLast reported by owners Mar 2026Reviewed Mar 2026

Frequently Asked Questions

What are the most common Kia Cadenza problems?

According to Au7o's analysis of 240+ owner reports, the 2020-2020 Kia Cadenza has 3 documented issues. The most frequently reported are: 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure, Panoramic Sunroof Glass Spontaneous Shattering, 6-Speed Automatic Transmission Hesitation and Hard Downshift. Of these, 2 are rated critical and should be addressed promptly.

Is the Kia Cadenza reliable?

The 2020-2020 Kia Cadenza has 3 known issues documented across 240+ owner reports. 2 issues are rated critical: 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure and Panoramic Sunroof Glass Spontaneous Shattering. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Kia Cadenza problems?

Repair costs for known Kia Cadenza issues range from $0 to $6,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure, typically costs $0-$6,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2014-2020 Kia Cadenza 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure?

The Cadenza's 3.3L Lambda II GDI V6 is covered under the Hyundai/Kia engine settlement for connecting rod bearing failure. Manufacturing debris in the crankshaft oil passages can restrict oil flow to the connecting rod bearings, causing premature wear and eventual engine seizure. Repairs typically run $0-$6,000. Severity: high.

What is the 2014-2020 Kia Cadenza Panoramic Sunroof Glass Spontaneous Shattering?

The Cadenza equipped with the panoramic sunroof has experienced instances of the tempered glass panel spontaneously shattering without external impact. The glass explodes with a loud pop, showering the interior with small tempered glass fragments. This appears to be caused by str… Repairs typically run $800-$1,500. Severity: high.

What is the 2014-2020 Kia Cadenza 6-Speed Automatic Transmission Hesitation and Hard Downshift?

The Cadenza's 6-speed automatic transmission (A6LF2) exhibits a hesitation or delayed response when accelerating from low speeds, particularly after coasting to a stop. The transmission seems to "hunt" for the right gear, causing a 1-2 second delay before power delivery. Hard dow… Repairs typically run $0-$2,000. Severity: medium.

2020 Kia Cadenza Problems: 3 Issues Every Owner Should Know

All 3 Known Issues

2014-2020 Kia Cadenza: 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure#

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

2014-2020 Kia Cadenza: Panoramic Sunroof Glass Spontaneous Shattering#

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

2014-2020 Kia Cadenza: 6-Speed Automatic Transmission Hesitation and Hard Downshift#

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

Other Kia Models

Frequently Asked Questions

What are the most common Kia Cadenza problems?

Is the Kia Cadenza reliable?

How much does it cost to fix common Kia Cadenza problems?

What is the 2014-2020 Kia Cadenza 3.3L Lambda II GDI V6 Connecting Rod Bearing Failure?

What is the 2014-2020 Kia Cadenza Panoramic Sunroof Glass Spontaneous Shattering?

What is the 2014-2020 Kia Cadenza 6-Speed Automatic Transmission Hesitation and Hard Downshift?