Does an oil change really fix this?

Sometimes — if low/dirty oil starved the actuator. About 30% of P0011 cases on Subarus clear after fresh oil and a 50-mile drive.

Why is this so common on Subarus?

The FB25 has tight VVT oil galleries that clog with sludge if oil changes are stretched. Stick to 5,000-mile intervals with 0W-20 synthetic.

Will an engine flush help?

Risky. A flush can break loose sludge that then plugs the VVT screen. If the engine is heavily sludged, do 2–3 short-interval oil changes instead.

How do I know if the actuator is bad?

If OCV tests good, oil is fresh, and the screen is clean — and P0011 still sets after a 50-mile drive — the actuator (on the cam sprocket) is mechanically worn.

P0011

Camshaft Position A — Timing Over-Advanced (Bank 1)

MODERATE

SystemVVT / Timing

Difficulty

Cost$40–$1100

Read10 min

What It Means Symptoms Common Causes Diagnosis Steps How to Fix It Emissions Test?Repair Cost FAQs

By Mike Reeves

ASE Master Technician (L1 Advanced Engine Performance) · 18 yrs

Technically reviewed by Sara Lopez

Last updated June 11, 2026

What Does P0011 Mean?

P0011 means the intake camshaft on bank 1 is more advanced (timed earlier) than the ECM commanded. Modern engines use variable valve timing (VVT) to optimize cam position for fuel economy and power; an oil-pressure-driven actuator on the cam sprocket rotates the cam relative to the chain.

On a Subaru with the FB25 boxer engine, P0011 is overwhelmingly caused by a stuck oil control valve (OCV), low oil pressure from sludge or dirty oil, or a clogged oil filter screen feeding the VVT actuator. Less commonly, the actuator itself fails mechanically. The fix ranges from a $40 oil change to a $1,000+ actuator job.

Symptoms

Check engine light with rough idle

VVT stuck advanced causes a noticeably lumpy idle.

Stalling at low RPM

Especially right after cold start.

Reduced fuel economy

Cam position wrong for the operating condition.

Hesitation off the line

Pronounced if the cam is stuck fully advanced.

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Common Causes

1.Low / dirty engine oil
35%
Sludge or low level starves the VVT actuator of pressure. Always check first.
2.Stuck oil control valve (OCV) solenoid
35%
Varnish on the spool prevents it from moving. Often cleanable.
3.Clogged VVT oil filter screen
15%
Subaru has a small mesh filter feeding the OCV — it clogs with sludge.
4.Failed cam actuator (mechanical)
10%
Internal locking pin or vanes worn. Requires actuator replacement.
5.Wiring / connector to OCV
5%
Corrosion or broken wire at the solenoid plug.

Step-by-Step Diagnosis

Check oil level and condition

Pull the dipstick. Level low? Top off and recheck after 50 miles. Oil black and sludgy? Do an oil and filter change with manufacturer-spec viscosity before anything else.

Pro TipOn the FB25, run only 0W-20 full synthetic. Conventional or 5W-30 in this engine accelerates the exact sludging that causes P0011.

Scan for related codes

P0011 alone? Pure VVT. P0011 + P0014 = both cams affected, suggests oil pressure or wiring. P0011 + P0521 = oil pressure sensor fault — fix that first.

> READ DTC
  P0011  Camshaft Position A — Over Advanced (B1)
  P0521  Engine Oil Pressure Sensor Range
  → Fix P0521 first

Test the OCV solenoid

Unplug the OCV (intake side, near the cam cover front). Resistance spec is typically 6.5–8.5 ohms. Apply 12V briefly — you should hear/feel the spool click.

WarningDon't apply 12V for more than a second or two. The solenoid will burn open if held energized.

Clean or replace the OCV and filter screen

Remove the OCV (one bolt) and the small mesh screen behind it. Soak both in carb cleaner, blow out with compressed air, reinstall with new O-ring. If the screen comes out shredded, do the engine flush before reassembly.

Recheck oil pressure

If the issue persists after a clean OCV and fresh oil, test oil pressure at the OCV port. Spec is 14 psi minimum at hot idle. Below that, you're chasing a failing oil pump or worn bearings.

How to Fix It

DifficultyTime 2–3 hrs

Parts needed:

Subaru OEM Oil Control Valve (FB25) — approx $85
OEM VVT Filter Screen Kit — approx $12
Subaru 0W-20 Synthetic Oil (5 qt) — approx $42
OEM Oil Filter (Tokyo Roki) — approx $9

Procedure:

Warm engine, drain oil, replace filter.
Refill with 0W-20 full synthetic to spec.
Locate OCV on front of intake-side cam cover.
Unplug connector, remove 10mm bolt.
Pull OCV straight out with O-ring intact.
Remove mesh filter screen behind OCV.
Clean both in carb cleaner and air-dry.
Reinstall with new O-ring, torque OCV bolt to 7 lb-ft.
Clear codes, drive 30 miles to allow VVT adaptation.

Will It Pass Emissions?

// DECISION TREE

STARTCheck engine light on?

YES →FAIL

NO →Readiness monitors set?

YES →PASS

NO →RETESTdrive 50–100 miles to set monitors

Repair Cost Breakdown

Part / Region	DIY Cost	Shop Labor	Total Range
Northeast / West Coast	$100	$340	$340–$520
Midwest / South	$95	$280	$280–$420
Worst-case (actuator + chain)	$340	$920	$960–$1,400

Estimates based on aggregated independent shop quotes; dealer labor adds 30–50%. Excludes diagnostic fee ($80–$150).

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FAQs

Short-term yes, but the cam stuck advanced increases combustion pressure and stresses the timing chain. Fix within a week or two.

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Sources & References

§SAE J2012 — Diagnostic Trouble Code Definitions — Standardized OBD-II code definitions used by all manufacturers.
§EPA OBD Regulations (40 CFR §86.1806-05) — Federal on-board diagnostic requirements for light-duty vehicles.

Cost figures are aggregated from real customer invoices at our shop plus quotes from RepairPal and Mitchell1 labor guides. Diagnostic procedures verified against factory service information (ALLDATA / Mitchell1).

// About the author

Mike Reeves — Independent shop owner in Phoenix, AZ. Specializes in driveability diagnostics on domestic and Asian gas engines. Writes our powertrain coverage. More about our team →

Related Codes

P0420MODERATE