P052E on Cadillac: How to Diagnose & Fix
Positive Crankcase Ventilation Regulator Valve Performance
1 Cadillac model · 1 documented issue · $150-$4,500 repair
P052E on Cadillac by model: symptoms, diagnosis and fix
Owners of four-cylinder CT5 550T (and CT4-shared LSY platform) models report higher-than-expected oil consumption, often exceeding GM's 'acceptable' threshold of one quart per ~2,000 miles. The valve-cover-integrated PCV system is a frequent contributor, and on worse cases worn piston rings or turbo seals allow oil into the combustion chamber. Symptoms commonly appear between 40,000 and 80,000 miles and are accompanied by low-oil warnings between changes, a lit check-engine light, and sometimes boost/lean codes. The PCV diaphragm is built into the valve cover, so a failed PCV requires valve-cover replacement rather than a standalone valve on some service variants.
Common Symptoms
- Frequent low-oil level warnings between oil changes
- Burning-oil smell or light blue exhaust smoke
- Rough idle or hesitation from a vacuum leak
- Check engine light with lean or boost-pressure codes
How to Fix
Have the dealer run a documented oil-consumption test; consumption beyond GM's spec can qualify for warranty repair. First-line fix is the PCV/valve-cover assembly (ACDelco PCV service part 12714149 applies to LSY CT5 on standalone-valve variants); persistent consumption after PCV service points to a piston-ring or turbo-seal repair under powertrain warranty. Maintain 5,000-mile changes with dexos1 Gen 3 0W-20 to protect the turbo and rings. Out-of-warranty PCV/valve-cover work is modest; a ring/teardown repair is the expensive end.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (1)
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 Cadillac?
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 Cadillac it is documented across 1 model: CT5.
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 Cadillac?
Published repair estimates on Cadillac range from $150 to $4,500 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.