P0520 on Kia: How to Diagnose & Fix
Engine Oil Pressure Sensor/Switch Circuit Malfunction
1 Kia model · 1 documented issue · 1 critical
P0520 on Kia by model: symptoms, diagnosis and fix
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.
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.
Owner tips & cautions
- 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
- WarningStop driving immediately if you hear knocking — continued driving can cause the rod to punch through the engine block, voiding warranty coverage
Sources for this issue (3)
P0520 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0520 mean on a Kia?
P0520 stands for "Engine Oil Pressure Sensor/Switch Circuit Malfunction." This code indicates a general electrical fault in the circuit for the engine oil pressure sensor or switch. The computer monitors this circuit to know your oil pressure, and it has detected a signal that is missing, shorted, or otherwise out of the expected electrical range. This is typically a wiring or sensor problem rather than an actual loss of oil pressure, but because oil pressure is critical to engine life, it should never be ignored until confirmed. If oil pressure truly is low, serious engine damage can result. On Kia it is documented across 1 model: Cadenza.
What are the most common causes of P0520?
The most common causes of P0520 are: Faulty oil pressure sensor or switch, Damaged, corroded, or loose wiring/connector at the sensor, Open or short in the sensor circuit wiring, Poor ground connection, Low engine oil level or genuinely low oil pressure, Failed PCM/ECM (less common). The specific cause varies by vehicle.
How much does it cost to fix P0520 on a Kia?
Repair costs vary widely with the root cause and Kia model; each issue on this page carries its own estimate where one is published.
Looking for P0520 on a different make?
View P0520 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.