P0524 on 2021-2024 Kia K5 2.5L: Engine Oil Pressure Too Low Causes and Fixes

What's Unique About the 2021-2024 Kia K5

The 2021-2024 Kia K5 with the Smartstream 2.5L GDI engine (G4KN) faces a unique combination of risks for this code. Firstly, these engines are known to have issues with excessive oil consumption, which can naturally lead to a low oil level and trigger P0524 if not monitored closely. Secondly, Kia issued a specific technical bulletin (PS719) warning that a plastic plug from the oil filter kit can easily fall into the filter housing during an oil change, blocking a critical oil passage and causing an immediate drop in pressure. Lastly, a more sinister and well-documented issue on the broader Smartstream 2.5L platform is the failure of the oil pump's pressure relief valve due to metal shavings from the manufacturing process, a problem detailed in Hyundai TSB 21-EM-003H for platform mates.

Symptoms You May Notice

• Oil pressure warning light illuminated on the dashboard (may flicker at idle when hot)
• Check Engine Light is on
• Engine making unusual knocking, ticking, or rattling noises
• Reduced engine performance or hesitation
• Engine stalling

Most Likely Causes

1. Critically Low Engine Oil Level 🔴 High Probability The Smartstream 2.5L GDI engine is documented to have excessive oil consumption issues, sometimes burning as much as a quart every 1,000 miles. Owners may be unaware of the rapid oil loss between changes, leading to a critically low level.
   How to confirm: Check the engine oil dipstick immediately (after waiting a few minutes for the oil to settle). If the level is below the minimum mark, this is the likely cause.
   Typical fix: Top off the oil to the correct level with the manufacturer-specified oil type (SAE 0W-20 Full Synthetic). Begin monitoring oil levels frequently (e.g., at every fuel fill-up) to establish the rate of consumption. An oil consumption test may be needed at a dealership per TSB 23-EM-008H.
   Est. part cost: $15-$30 for a quart of full synthetic oil.
2. Improper Oil Filter Installation (Blocked Passage) 🔴 High Probability → Shop Engine Oil Filter Adapter Per Kia TSB PS719, the oil filter kit (P/N 26350 2S000) includes a small plastic drain plug that can become dislodged and fall into the oil cooler assembly, blocking the engine's oil supply. This is a very common cause if the P0524 code appears immediately after an oil change.
   How to confirm: This is a strong possibility if the P0524 code appeared right after an oil and filter change. A technician must remove the oil filter and inspect the oil filter housing for a loose plastic plug obstructing the oil passage.
   Typical fix: Remove the oil filter and the foreign object (the plastic drain plug) from the oil filter housing. Install a new, correct oil filter, ensuring no parts are left behind.
   Est. part cost: $15-$25 for a new OEM oil filter kit.
3. Failing Oil Pump (Stuck Relief Valve) 🟡 Medium Probability → Shop Engine Oil Pump Platform mates like the Hyundai Sonata and Santa Fe with the same 2.5L engine have a documented issue where metal shavings from manufacturing jam the oil pump's pressure relief valve open, causing a genuine loss of pressure, especially at hot idle. This is covered by Hyundai TSB 21-EM-003H.
   How to confirm: If the oil level is full and the oil filter housing is clear, a mechanical pressure test is needed. If the pressure is below spec (e.g., under 8.5 PSI at warm idle), the oil pump is the primary suspect.
   Typical fix: Complete replacement of the oil pump assembly, which involves removing the oil pan.
   Est. part cost: $200-$300 for the pump, with total repair cost ranging from $800-$1,200 due to labor.
4. Faulty Engine Oil Pressure Sensor/Switch ⚪ Low Probability While less common on this platform than mechanical causes, the sensor can still fail. On these engines, a faulty sensor is a less likely cause of P0524 compared to actual pressure loss.
   How to confirm: After confirming the oil level is correct and passages are clear, a technician connects a mechanical oil pressure gauge. If the mechanical gauge shows normal pressure (e.g., 8.5+ PSI at idle, 28.4+ PSI at 2,000 RPM) while the scan tool reports low pressure, the sensor is faulty.
   Typical fix: Replace the engine oil pressure sensor and clear the code.
   Est. part cost: $40-$100 for the sensor (OEM P/N 94750-2M454).

Rare But Worth Checking

• Clogged Oil Pickup Tube: This is a true mechanical failure. The pickup tube screen in the oil pan can become clogged with sludge or debris (potentially related to the manufacturing debris issue), starving the pump of oil. This would be investigated during an oil pump replacement.
• Worn Internal Engine Components: Excessive wear on engine bearings (rod bearings, main bearings) can cause a drop in overall oil pressure. This is a worst-case scenario, often accompanied by audible engine knock, and typically requires an engine rebuild or replacement. This would be the result of driving for an extended period with low oil pressure.

Diagnosis Steps

1. Immediately and safely stop the vehicle and turn off the engine.
2. Check the engine oil level using the dipstick. If low, top it off with SAE 0W-20 full synthetic oil and see if the light and code clear. If the oil level is extremely low, the engine may already be damaged.
3. If the P0524 code appeared immediately after an oil change, the top priority is to suspect a blocked oil passage per TSB PS719. Have the oil filter housing inspected for a dislodged plastic drain plug.
4. Connect a scan tool to confirm the P0524 code is active.
5. CRITICAL STEP: Connect a mechanical oil pressure gauge to the engine to measure the actual oil pressure. Compare this reading to the manufacturer's specifications: at least 8.5 PSI at warm idle and 28.4 PSI at 2,000 RPM.
6. If mechanical pressure is NORMAL, the problem is electrical. Inspect the oil pressure sensor wiring and connector for damage or oil contamination. If the wiring is good, replace the oil pressure sensor (P/N 94750-2M454).
🎬 See: How to locate and replace the oil pressure sensor
7. If mechanical pressure is LOW, the problem is mechanical. With the oil level full and passages clear, the most likely cause is a failing oil pump. This requires removing the oil pan for inspection and replacement of the oil pump and pickup tube.

Parts You'll Likely Need

• Engine Oil — The most common cause is a low oil level due to the engine's tendency to consume oil. SAE 0W-20 Full Synthetic is required.
  Trusted brands: Pennzoil, Mobil 1, Castrol
  Aftermarket price range: $15-$30 (per quart)
• Service Kit-Oil Filter (OEM #26350-2S000) — Required for an oil change. A specific failure mode related to this kit's plastic drain plug can cause P0524 if installed incorrectly, as noted in TSB PS719.
  Trusted brands: Kia (Genuine), Hyundai (Genuine)
  OEM price range: $15-$25
  Aftermarket price range: $10-$20
• Engine Oil Pressure Sensor (OEM #94750-2M454) — If the oil level and pressure are confirmed to be good with a mechanical gauge, the sensor itself is the next likely culprit, providing false readings to the ECM.
  Trusted brands: Kia (Genuine), Bosch
  OEM price range: $60-$120
  Aftermarket price range: $30-$70
• Engine Oil Pump Assembly (OEM #21310-2S100 (example from platform mate)) — A known failure point on the 2.5L Smartstream platform where manufacturing debris jams the pressure relief valve, requiring complete replacement.
  Trusted brands: Kia (Genuine), Hyundai (Genuine)
  OEM price range: $200-$300

Technical Service Bulletins (TSBs) & Recalls

• PS719 / PS719_R1 (December 2021, Revised Sep 2022): Warns of potential low oil pressure if the drain plug from the oil filter service kit (26350 2S000) is left in the oil filter housing during an oil change.
• 23-EM-008H: Addresses excessive oil consumption issues related to the piston ring design in the Smartstream 2.5L GDI engine.
• Hyundai TSB 21-EM-003H: Relevant for platform mates, this TSB describes the procedure for addressing P0524 caused by a sticking oil pump pressure relief valve due to manufacturing debris.

Platform-Specific Known Issues

• Excessive Oil Consumption: The Smartstream 2.5L GDI (G4KN) engine is subject to TSB 23-EM-008H for high oil consumption, which is a primary contributor to low oil levels and the P0524 code.
• Oil Change Hazard: TSB PS719 highlights a critical risk during oil changes where a plastic part from the filter kit can block an oil passage, causing this code and potential engine damage.
• Oil Pump Failure Pattern: While not specific to the K5 via a Kia TSB, the identical engine in Hyundai models has a well-documented pattern of oil pump failures from debris, as detailed in Hyundai TSB 21-EM-003H.

Mechanic-Grade Diagnostic Values

• Mechanical Engine Oil Pressure at Warm Idle — expected: 8.5 PSI or greater. Failure: A reading below 8.5 PSI confirms a true mechanical low-pressure condition.
• Mechanical Engine Oil Pressure at 2,000 RPM (Warm) — expected: 28.4 PSI or greater. Failure: A reading below 28.4 PSI under load points towards a significant mechanical lubrication issue.
• Oil Pressure Switch Continuity (Engine Off) — expected: Continuity (near 0 Ohms resistance). Failure: An open circuit (infinite resistance) with the engine off indicates a faulty switch.
• Oil Pressure Switch Continuity (Engine Running) — expected: No continuity (open circuit). Failure: Continuity (near 0 Ohms resistance) with the engine running and oil pressure present indicates the switch is stuck closed.

Wiring & Ground Locations

• Oil Pressure Sensor Connector — The sensor is typically mounted on the engine block, often near the oil filter housing assembly.. The sensor's single-wire connector and the wire itself should be inspected for physical damage, corrosion, or being contaminated with oil, which can cause a false signal to the ECM.

Real Owner Repair Stories

• Multiple technical articles and videos referencing Hyundai TSB 21-EM-003H (2020-2021 Hyundai Sonata / Santa Fe with Smartstream 2.5L GDI engine (platform mate to Kia K5)) — Flickering red oil pressure warning light at hot idle, with P0524 code stored, even when the engine oil level is full.
  ❌ Tried (didn't work) Topping off or changing the engine oil., Replacing the oil pressure sensor without verifying mechanical pressure first.
  ✅ What actually fixed it Complete replacement of the engine oil pump assembly (P/N 21310-2S100). The original pump's pressure relief valve was found to be stuck open due to metal shavings from the manufacturing process.
• Kia Technical Service Bulletin PS719 (2021+ Kia K5 with 2.5L GDI engine) — DTC P052400 and/or engine noise appearing immediately after an engine oil and filter service.
  ❌ Tried (didn't work) Standard diagnostic procedures that don't account for the recent service history.
  ✅ What actually fixed it Removing the oil filter and finding the small plastic drain plug from the new filter kit (P/N 26350 2S000) had fallen into and was obstructing the oil supply passage in the oil cooler assembly. The fix was to remove the obstruction and correctly install a new filter.

OEM Part Supersession History

• 21310-2S000 → 21310-2S500 — Part number update or revision.
  Heads up: This supersession applies to the 2.5L Turbo engine. The non-turbo 2.5L GDI specified in this article uses P/N 21310-2S100, for which no supersession was found.

Model Year Variations Within This Range

• 2021-2022: A recall (SC214) was issued for some 2021-2022 K5 models with the 2.5L *turbocharged* engine concerning a potential fuel leak at the high-pressure pump. While not directly related to the P0524 code on the non-turbo engine, it indicates manufacturer activity and potential revisions in this period.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• 8-Speed Wet Dual-Clutch Transmission (DCT) Failure 🔴 High — Primarily affects GT models. Can occur at very low mileage (<5,000 miles). Symptoms include shuddering, slipping, loss of even/odd gears, or total failure to engage. (Ref: Service Action SA502 (superseded by SA526) for logic improvement. Some cases require full transmission replacement.)
• Fuel Tank Melting Risk (1.6T Engine) 🔴 High — Affects 2021-2024 K5 models with the 1.6L Turbo engine, not the 2.5L. A faulty check valve can cause the fuel tank to expand and melt from exhaust heat. (Ref: Kia Recall SC356 / NHTSA Recall 23V149000)
• Infotainment System Glitches 🟡 Low — Common across many model years. Issues include the screen freezing, going blank, or wireless Apple CarPlay/Android Auto disconnecting frequently.
• Premature Brake Wear 🟠 Medium — Owners report premature warping of rotors and rapid wear of brake pads, sometimes requiring service well before 20,000 miles.
• Side Curtain Airbag Malfunction 🔴 High — Affects certain 2021-2023 K5 vehicles where airbags may have been installed incorrectly, preventing proper deployment. (Ref: NHTSA Recall affecting some 2021-2023 models.)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific code, a used part is only a reasonable choice for the oil pressure sensor (P/N 94750-2M454). Sourcing one from a low-mileage, verified-running donor vehicle can be a cost-effective alternative to a new part.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For a sensor, ensure the electrical connector is free of corrosion, oil contamination, and physical damage.
• Verify the donor vehicle was not involved in a front-end collision.
• Ask for the VIN to check the donor vehicle's history for any signs of major engine trouble.

OEM-only on this vehicle (don't cheap out):

• Engine Oil Pump Assembly: DO NOT use a used oil pump. The primary cause of failure is manufacturing debris, meaning a used pump from the same era has a very high likelihood of having the same defect. Only a new OEM part should be used.
• Engine Assembly: A used Smartstream 2.5L GDI engine is a significant gamble due to widespread, documented issues with excessive oil consumption. A replacement engine should ideally be new or remanufactured with documentation of updates to address this issue.

Brands owners have reported issues with on this vehicle:

• Unbranded or 'white-box' oil filters. Given the specific TSB (PS719) related to the OEM filter kit's drain plug, using a non-OEM filter could introduce other unforeseen fitment issues. Stick with the genuine Kia/Hyundai filter (P/N 26350-2S000).

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P1191 — Often associated with oil pressure and delivery issues on this platform, specifically referenced in technical alerts regarding the oil filter housing blockage.
• P0520 — Engine Oil Pressure Sensor/Switch Circuit malfunction; related when the P0524 is caused by an electrical failure of sensor P/N 94750-2M454 rather than a mechanical loss of pressure.
• P0300 — Random or Multiple Cylinder Misfire; can occur as a result of the hesitation and reduced engine performance symptoms associated with critical oil pressure loss.

Frequently Asked Questions