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Severity: Moderate Code type: Generic (all makes)

P0011 Code: "A" Camshaft Timing Over-Advanced or Performance (Bank 1)

The bank 1 intake cam sits further advanced than the PCM asked for, usually an oil or control valve issue.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
"A" Camshaft Timing Over-Advanced or Performance (Bank 1)
System
Fuel & Air Metering · Powertrain
Safe to drive?
With caution
Typical repair cost
$50–$2,400
DIY difficulty
Moderate

On bank 1 the intake camshaft rides on a hydraulic phaser that the PCM can rotate several dozen crankshaft degrees ahead of its resting position. The PCM works out the real cam angle by comparing the cam sensor pulses with the crankshaft sensor and checks it against the angle it is commanding. P0011 sets when the actual angle stays ahead of the target for too long, or when the phaser answers commands too slowly. In most cases oil keeps reaching the advance chamber when it shouldn't, because the oil control valve is sticking or the oil itself is low, sludged or thicker than specified. An intake cam left advanced at idle opens the intake valves while the exhaust valves are still open, which is why this code so often comes with a lumpy idle or a stall at stoplights.

Can I keep driving? You can usually drive carefully to a shop, but expect a shaky idle and possible stalling when you stop, which is a real nuisance in traffic. Check the oil level before any drive; running a phaser engine low on oil also starves the hydraulic chain tensioner.

Try this first – 5-minute fix

  1. Check the oil level properly Park on level ground, switch the engine off and wait five minutes, then read the dipstick. Being a quart or more low is enough to upset the phaser on many engines, so top up with the oil your manual calls for.
  2. Change the oil if it's overdue or the wrong grade If the oil is black and thick, past its change interval, or you don't know what went in last time, change oil and filter using exactly the viscosity printed on the filler cap or in the owner's manual. Heavier-than-specified oil is a classic trigger for P0011.
  3. Clear the code and drive a full cycle Clear the code and drive 20 to 30 minutes with some idling, city stops and highway speed. If it stays away for a few days, oil was the culprit; if it comes back, work through the diagnostic steps below.

How to read P0011

How to read P0011P10203114
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 0 Fuel/air & emissions (aux.)
  4. 11 Specific fault

Symptoms

  • Rough, lumpy idle once the engine is warm
  • Engine stalls or nearly stalls when you roll to a stop
  • Hesitation when pulling away from a standstill
  • Check engine light, sometimes with a misfire code on a cold morning
  • Fuel economy a few mpg worse than usual
  • Short rattle from the front of the engine right after startup on some engines

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Oil level low, or oil overdue and sludged so it no longer drains from the phaser properly 28%
  2. Oil control valve sticking partly open from varnish or metal particles 24%
  3. Wrong viscosity, such as 10W-30 or 5W-40 in an engine specified for 0W-20 14%
  4. Clogged mesh screen in the oil passage feeding the control valve 12%
  5. Phaser binding internally or leaking past worn vane seals 10%
  6. Stretched timing chain throwing off the measured cam angle 8%
  7. PCM calibration issue addressed by a software update 4%

Diagnosis step by step

Diagnostic flow: P00111Compare desired and actual intakecam angle2Command the phaser at idle3Pull and bench-check the oil controlvalve4Swap valves if both cams use thesame part5Look for a hidden oil screen6Rule out timing chain stretch

  1. Compare desired and actual intake cam angle

    With the engine fully warm and idling, watch the bank 1 intake cam desired and actual values in live data. Most engines command the parked position at idle, so an actual reading stuck several degrees advanced while zero is commanded proves the phaser isn't returning home.

    Tools: OBD-II scanner

  2. Command the phaser at idle

    Use the scan tool's bi-directional control to advance the intake cam at idle. A healthy system makes the idle drop and stumble within a second or two and recovers as soon as you release the command. No reaction at all, or a stumble that hangs on afterwards, points to a valve or phaser that sticks.

    Tools: OBD-II scanner

  3. Pull and bench-check the oil control valve

    Remove the bank 1 intake control valve, usually held by one bolt on the front or top of the cylinder head. Look for varnish, glittering metal or sludge on the spool and a torn or plugged screen around its ports. Short 12-volt taps across the pins should make the spool snap in and out cleanly; never hold power on for more than a second or two.

    Tools: Screwdriver, Flashlight, Multimeter

  4. Swap valves if both cams use the same part

    On many dual-VVT engines the intake and exhaust valves are interchangeable. Swap them, clear the code and drive; if the fault moves to the exhaust side as P0014, the valve you moved is the problem.

    Tools: OBD-II scanner, Screwdriver

  5. Look for a hidden oil screen

    Some engines hide a small mesh filter in the passage feeding the valve, behind a plug on the cylinder head or in a cam cap. A plugged or collapsed screen, typical after a sludge episode, makes the phaser respond erratically and must be cleaned or renewed.

    Tools: Flashlight

  6. Rule out timing chain stretch

    If oil and valve check out and P0016 has joined the party, the cam may simply read wrong because the chain has grown. Check the crank-to-cam correlation value in live data and inspect chain, guides and tensioner before condemning the phaser.

    Tools: OBD-II scanner

Where the parts are

Ignition: coils and spark plugs per cylinder – P00111234567
Ignition: coils and spark plugs per cylinder
  1. 1Ignition coil
  2. 2Spark plug
  3. 3Fuel injector
  4. 4Camshaft sensor
  5. 5Crankshaft sensor
  6. 6Engine computer (ECM)
  7. 7Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Oil and filter change with the specified viscosity Yes $50–$120
Replace bank 1 intake oil control valve Yes $120–$350
Clean oil control valve screen and feed passage No $100–$300
Replace intake cam phaser No $600–$1,500
Timing chain, guides and tensioner kit No $1,000–$2,400

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Toyota

Several Toyota VVT-i four-cylinders, such as the 2AZ-FE in the Camry and RAV4, have a small filter screen for the oil control valve behind a plug in the cylinder head. When oil changes have been stretched, that screen clogs and timing codes follow, so it's worth checking before buying parts.

Chevrolet

The 2.4 Ecotec in the Equinox and Malibu is known for burning oil between changes. Many P0011 cases on this engine start with a low oil level, and the same engine is prone to chain stretch, so a P0011 that returns with P0016 deserves a timing chain inspection.

P0011 on Chevrolet in detail

Hyundai

On Hyundai and Kia 2.0 and 2.4 GDI four-cylinders, a sticking CVVT oil control valve and low oil level from consumption are common reasons for intake timing codes. Check the level first; the valve itself bolts onto the front of the cylinder head and is easy to reach.

P0011 on Hyundai in detail

Field data

Chevrolet 40
Hyundai 17
GMC 8 Terrain, Sierra 1500
Kia 6 Optima, Soul Ev, Forte
Ford 5 Escape, F-150 REGULAR CAB, F-150 SUPERCAB
Nissan 5 Maxima, 370z, Altima
Subaru 4 Crosstrek, Impreza, IMPREZA WRX/STI
Volkswagen 4 Jetta Sportwagen, Cc, Jetta

Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.

Emissions / smog test impact

Will fail

Any code that lights the check engine lamp fails the OBD-II plug-in test used by state emissions programs. Since the oil fix is quick, change the oil, clear the code and complete a couple of drive cycles so the readiness monitors show complete before you retest.

Frequently asked questions

Can the wrong oil really set P0011?

Yes. Cam phasers are designed around a specific viscosity. Oil that is thicker than specified drains from the advance chamber too slowly, so the cam lags on its way back home and the PCM sees it parked too far advanced.

Why does the engine stall at stoplights with this code?

When the intake cam stays advanced at idle, the intake valves open while the exhaust valves haven't closed yet. That overlap pushes exhaust gas back into the intake, and the idle can't stay steady, especially with the A/C on or the transmission in Drive.

Will an engine flush or oil additive fix it?

Fresh oil sometimes frees a sticky control valve, but aggressive flushes can loosen sludge that then blocks the very screen feeding the phaser. A normal oil change followed by cleaning or replacing the valve is the safer route.

How much does P0011 usually cost to fix?

If it's the oil, under about $120. An oil control valve is typically $120 to $350 installed. It only gets expensive, $1,000 and up, when the phaser or the timing chain is worn out.

Sources