P052E on Infiniti: How to Diagnose & Fix
Positive Crankcase Ventilation Regulator Valve Performance
1 Infiniti model · 1 documented issue · $200-$4,000 repair
P052E on Infiniti by model: symptoms, diagnosis and fix
The M274 four-cylinder in the 2.0t burns noticeably more oil than owners expect, and consumption climbs with mileage. Reports commonly describe roughly a quart per 3,000 miles once the car passes 60,000 miles, with worse cases burning a quart every 1,500 miles. The usual contributors are piston ring wear and coking, valve stem seal hardening, and the crankcase ventilation system pulling oil vapor into the intake. Because the Q50 has no oil dipstick on this engine — the level is read through the instrument cluster — owners often do not notice the loss until the low-oil warning appears, and running the engine chronically low is what turns oil consumption into timing chain and bearing damage.
Common Symptoms
- Low oil level warning between scheduled oil changes
- Consumption of a quart or more every 1,500 to 3,000 miles
- Blue smoke on startup or under hard acceleration
- Oil smell from the engine bay
- Fouled spark plugs or misfires at higher mileage
How to Fix
Check the oil level through the vehicle information display at every other fuel fill rather than waiting for a warning, and keep a quart of the correct spec oil in the trunk. Establish the real consumption rate over a measured interval before authorizing repairs. If consumption exceeds roughly a quart per 1,000 miles, have the shop check crankcase pressure and inspect the PCV/crankcase pressure regulator in the cam cover — a failed diaphragm there is the cheapest cause and often sets a crankcase pressure code. Persistent blue smoke on startup after sitting points to valve stem seals; smoke under sustained load points to rings. Shortening the oil change interval to 5,000 miles with full synthetic slows ring coking. Expect the shop to also clean carbon from the intake valves on a direct-injected engine at this mileage.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti M274 oil-separator/breather assemblyOEM130G5-90C2N / 11830-HG00C
Confirmed crankcase-ventilation/oil-separator failure branch Fitment/availability: 11830-HG00C is cataloged for Q50 2LTURBO and superseded by current 130G5-90C2N, which the official store describes as the oil-separator assembly including…
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Sources for this issue (3)
P052E 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 P052E mean on a Infiniti?
P052E stands for "Positive Crankcase Ventilation Regulator Valve Performance." P052E indicates a performance problem with the positive crankcase ventilation (PCV) regulator valve, the valve that meters blow-by gases from the engine crankcase back into the intake to be burned. The computer monitors crankcase pressure or related readings, and when the PCV regulator isn't controlling flow within the expected range, it sets this code. Symptoms can include rough idle, oil leaks from seals due to pressure imbalance, whistling/sucking noises, or increased oil consumption. It points to the PCV valve or ventilation system rather than the fuel or ignition system. On Infiniti it is documented across 1 model: Q50.
What are the most common causes of P052E?
The most common causes of P052E are: Stuck, clogged, or failed PCV regulator valve, Cracked or disconnected PCV hose/line, Vacuum leak in the crankcase ventilation system, Clogged PCV passages from sludge or carbon, Faulty crankcase pressure sensor, Damaged valve cover with integrated PCV (where applicable), Wiring or connector fault on electrically controlled PCV valves. The specific cause varies by vehicle.
How much does it cost to fix P052E on a Infiniti?
Published repair estimates on Infiniti range from $200 to $4,000 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 P052E on a different make?
View P052E 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.