INFINITI FX50 (2009-2013) Engine Oil Pressure Switch Guide
Understanding the oil pressure warning light on your FX50 and how to fix it.
- A flickering oil light is often a faulty switch, not low oil pressure, but you must verify the oil level immediately.
- The switch can leak oil externally; check the sensor itself for wetness.
- Use a quality aftermarket brand like Beck Arnley or Standard Ignition for reliability.
- Be careful not to overtighten the new switch to avoid damaging the engine block.
Is Your Oil Light On? Understanding the Problem
Seeing the red oil pressure light flicker on your INFINITI FX50's dashboard can be alarming. While it can indicate a serious internal engine problem, it is often caused by a failure of the oil pressure switch itself. These switches can fail in a few ways: they can start leaking oil externally, they can fail internally and provide a false reading, or they can get stuck, preventing a warning when there's a real pressure drop. Before assuming the worst about your engine, it's important to properly diagnose the issue, as a faulty switch is a common and relatively inexpensive fix.
A Note on Thread Type
Many INFINITI and Nissan engines use a British Standard Pipe Thread (BSPT) for the oil pressure switch. This is different from the National Pipe Taper (NPT) common on domestic vehicles. Using a switch with the wrong thread type can damage the engine block and cause leaks. It is critical to use a part specifically listed as compatible with your 2009-2013 FX50. A Reddit user learned this the hard way, cracking the upper oil pan by overtightening a switch with the wrong thread.
Choosing the Right Aftermarket Part
For a simple but crucial part like an oil pressure switch, you don't necessarily need to buy an expensive OEM part from the dealer. However, you should stick to reputable aftermarket brands to ensure reliability. Here’s a breakdown of the available brands:
- Top Tier (OEM-Equivalent): Brands like Beck Arnley and Standard Ignition (SMP) have a long-standing reputation for quality. Beck Arnley, in particular, often sources parts that meet or exceed original specifications for form, fit, and function, making them a trusted choice for Japanese vehicles.
- Mid-Tier (Reputable Aftermarket): Brands like Vemo and Facet are also available. While they can be a cost-effective option, quality can sometimes be more variable than the top-tier brands.
- Economy Tier: Lesser-known brands like Global Parts or other unbranded options are the most affordable but carry the highest risk of premature failure. Given the critical function of this part, spending a few extra dollars for a reputable brand is highly recommended.
Pro Tip: Check for Leaks First
Before you buy a new switch, put on some gloves and feel around the existing oil pressure switch on your engine. They are known to leak oil from the seam where the plastic connector is joined to the metal body. If you see or feel fresh oil on the switch, you’ve found your problem.
Cost of Replacing an INFINITI FX50 Oil Pressure Switch
| Part/Service | Estimated Cost |
|---|---|
| New OEM Switch | $35 - $60 |
| New Aftermarket Switch | $14.53 - $40.77 |
| Shop Labor | $50 - $100 |
| Total (DIY Aftermarket) | $15 - $41 |
| Total (Shop Installed Aftermarket) | $65 - $141 |
Frequently Asked Questions (FAQ)
Where is the oil pressure switch located on a 2009-2013 FX50?
The oil pressure switch is typically located on the engine block, often near the oil filter housing. On many Nissan/INFINITI V8 engines, it is accessible from underneath the vehicle after removing a protective splash shield.
Is there a recall for the FX50 oil pressure switch?
No, there are no specific recalls for the oil pressure switch on the 2009-2013 INFINITI FX50. There was a recall for some 2011 FX models related to oil cooler connector bolts that could break and cause an oil leak, which would also trigger the oil pressure light. However, this did not involve the switch itself.
What tools are needed to replace the oil pressure switch?
You will typically need a deep socket (often 1 1/16" or a metric equivalent), a ratchet, and possibly a small extension. It's also wise to have some shop towels ready to clean up any minor oil drips. A torque wrench is recommended for proper installation to avoid damaging the threads.
What does the trouble code P0520 mean?
P0520 stands for "Engine Oil Pressure Sensor/Switch 'A' Circuit Malfunction." This code is set when the vehicle's computer sees a problem in the oil pressure switch circuit. It can be caused by a faulty switch, damaged wiring, or a genuine oil pressure problem.
Technical Specifications
OEM Part Numbers: 25240-4M400 25240-4M40E
Single-pin (1-pin) electrical connector. Uses British Standard Pipe Thread (BSPT), not NPT.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI FX50: