P0521 on Infiniti: How to Diagnose & Fix
Engine Oil Pressure Sensor/Switch Range/Performance
1 Infiniti model · 1 documented issue · 1 critical · $400-$1,400 repair
P0521 on Infiniti by model: symptoms, diagnosis and fix
On pre-2012 VQ37VHR engines the cam cover gaskets fail and leak, and unlike an ordinary valve cover weep this one matters mechanically: the leak path bleeds down oil pressure feeding the top end. Low oil pressure on this engine starves the VVEL assembly and the cam and rod bearings, and owners who dismiss the leak as a minor seep have lost engines to it. The visible signs are oil pooling in the spark plug wells, oil on the exhaust manifolds producing a burning smell and smoke from under the hood, and a low oil pressure warning or gauge reading that comes up at idle when hot.
Common Symptoms
- Oil pooled in the spark plug wells
- Burning oil smell and smoke from the engine bay
- Low oil pressure warning, especially at hot idle
- Visible oil on the exhaust manifolds or down the block
- Misfires from oil-fouled ignition coils
- Ticking from the top end that worsens when warm
How to Fix
Treat a cam cover leak on a pre-2012 G37 as urgent rather than cosmetic, particularly if it is accompanied by any low oil pressure indication. Replace both cam cover gaskets along with the spark plug tube seals and the half-moon seals, and inspect the plug wells for oil that has soaked the coil boots — oil-fouled coils cause misfires that get misdiagnosed as ignition failure. Verify actual oil pressure with a mechanical gauge rather than trusting the dash indication before and after the repair. If pressure remains low with the gaskets fixed, stop driving the car and investigate the oil pump and pickup, since continued operation at low pressure will destroy the bearings. Use OEM gaskets here; aftermarket sets have a poor record of resealing on this engine.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- OEM VQ37VHR valve-cover gasket and tube-seal selectionsOEM13270-EY01A / 13270-EY01B / 13271-EY00A
Confirmed external valve-cover leak repair with selectable left/right gaskets and tube seals Fitment/availability: Fits 2008-2013 G37 Coupe and the listed later Sedan/Convertible VQ37VHR branches.
- OEM VQ37VHR valve-cover and gasket kitOEMZ1 assembled OEM VQ37VHR valve-cover kit
Do not replace sound covers merely because the serviceable perimeter gasket leaks; confi
- Nissan OEM fluid-gasket RTVOEMNissan OEM fluid gasket RTV
Small specified-joint sealant branch for the valve-cover procedure Fitment/availability: Use only at the service-manual junctions and in the specified bead size; it does not replace molded cover gaskets and excess RTV can contaminate oil…
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Sources for this issue (2)
P0521 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 P0521 mean on a Infiniti?
P0521 stands for "Engine Oil Pressure Sensor/Switch Range/Performance." This code indicates the engine oil pressure sensor or switch is sending a reading that is implausible or out of its normal operating range — for example, the value doesn't match what the engine's speed and conditions should produce. Unlike a simple circuit fault, this means the signal is present but doesn't make sense (range/performance). It can be caused by a failing sensor, wiring issues, or by genuinely abnormal oil pressure. Because oil pressure protects the engine, a true low-pressure reading should be confirmed and taken seriously. On Infiniti it is documented across 1 model: G37.
What are the most common causes of P0521?
The most common causes of P0521 are: Faulty or worn oil pressure sensor/switch, Low engine oil level or actual abnormal oil pressure, Wiring or connector corrosion/damage at the sensor, Sludge or debris affecting the sensor reading, Use of incorrect oil viscosity, Failing oil pump, Poor electrical ground. The specific cause varies by vehicle.
How much does it cost to fix P0521 on a Infiniti?
Published repair estimates on Infiniti range from $400 to $1,400 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0521 on a different make?
View P0521 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.