If your OBD-II scanner displays P0008, your vehicle’s Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected that the camshaft and crankshaft timing on Bank 1 are no longer properly synchronized.
The engine depends on exact timing between the crankshaft and camshafts. The crankshaft controls piston movement, while the camshafts open and close the intake and exhaust valves. If the ECM determines that the position of one or more Bank 1 camshafts does not match the expected crankshaft position, it stores P0008 and illuminates the Check Engine Light.
P0008 is commonly associated with:
- A stretched timing chain
- A worn timing chain tensioner
- Damaged timing guides
- Incorrect mechanical timing
- A failing camshaft actuator
- Low or contaminated engine oil
- Crankshaft or camshaft position sensor problems
This can be a serious code because incorrect valve timing can reduce performance, cause misfires and, on interference engines, potentially result in internal engine damage.
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P0008 Quick Facts
| Item | Information |
|---|---|
| OBD-II code | P0008 |
| Official description | Engine Position System Performance Bank 1 |
| Category | Powertrain |
| System | Engine timing and variable valve timing |
| Code type | Generic SAE powertrain code |
| Severity | High |
| Safe to drive? | Limited driving only; diagnose promptly |
| Most common causes | Stretched timing chain, worn tensioner, incorrect timing, low oil pressure |
| Typical repair cost | $150–$4,000+ |
What Does the P0008 Code Mean?
P0008 means “Engine Position System Performance Bank 1.”
The ECM uses signals from the crankshaft position sensor and camshaft position sensors to determine whether the engine’s mechanical timing is correct.
During normal operation, the camshafts must remain synchronized with the crankshaft within a very narrow range. If the ECM detects that the camshaft timing on Bank 1 has moved outside the expected position, it stores P0008.
Bank 1 is the side of the engine containing cylinder number one.
On an inline engine, there is only one cylinder bank, so Bank 1 refers to the entire engine.
P0008 is closely related to:
- P0009: Engine Position System Performance Bank 2
- P0016: Crankshaft Position–Camshaft Position Correlation Bank 1 Sensor A
- P0017: Crankshaft Position–Camshaft Position Correlation Bank 1 Sensor B
- P0018: Crankshaft Position–Camshaft Position Correlation Bank 2 Sensor A
- P0019: Crankshaft Position–Camshaft Position Correlation Bank 2 Sensor B
P0008 often indicates a broader mechanical timing problem affecting multiple camshafts on Bank 1 rather than one isolated sensor circuit.
How Engine Timing Works
The crankshaft converts piston movement into rotational force. The camshafts control when the intake and exhaust valves open and close.
A timing chain, timing belt or gear set connects these components and keeps them synchronized.
When the system is correctly timed:
- Pistons move at the correct moment.
- Intake valves open during the intake stroke.
- Exhaust valves open during the exhaust stroke.
- Combustion occurs efficiently.
- The engine produces normal power.
Modern engines may also use variable valve timing to adjust camshaft position while the engine is running.
The ECM controls this system using:
- Camshaft actuators or phasers
- Oil control valves
- Variable valve timing solenoids
- Camshaft position sensors
- Crankshaft position sensors
- Engine oil pressure
If mechanical wear or hydraulic problems prevent the camshafts from reaching the commanded position, P0008 may be stored.
Symptoms of the P0008 Code
Symptoms can range from a Check Engine Light with mild performance loss to severe engine noise and a no-start condition.
Common symptoms include:
- Illuminated Check Engine Light
- Rough idle
- Engine misfires
- Reduced engine power
- Poor acceleration
- Hard starting
- Extended cranking
- Engine stalling
- Poor fuel economy
- Rattling noise during startup
- Timing chain noise
- Hesitation
- Limp mode
- Increased exhaust emissions
- Failed emissions inspection
- Engine cranks but will not start
A stretched timing chain may initially cause only a brief rattle when the engine starts. As the chain continues to wear, the timing deviation can become large enough to affect drivability.
Common Causes of P0008
1. Stretched Timing Chain
A stretched timing chain is one of the most common causes of P0008.
Timing chains do not literally stretch like rubber. Instead, wear develops at the chain pins, links and sprockets, increasing the chain’s effective length.
As the chain wears:
- Camshaft timing becomes delayed.
- The tensioner reaches the end of its travel.
- Startup rattles may develop.
- Camshaft correlation values move outside specification.
- P0008 may be stored.
Chain wear is more likely on engines with:
- Extended oil-change intervals
- Low oil levels
- Poor-quality oil
- High mileage
- Known timing-chain design issues
2. Failed Timing Chain Tensioner
The timing-chain tensioner keeps the chain tight as it rotates.
Many modern tensioners depend on engine oil pressure. If the tensioner fails or loses pressure, the chain can become loose and allow the camshaft timing to fluctuate.
Possible tensioner problems include:
- Internal wear
- Weak spring
- Oil-pressure loss
- Sludge blockage
- Mechanical collapse
- Failure to hold pressure after shutdown
A failing tensioner often causes a rattling sound during cold startup.
3. Damaged Timing Chain Guides
Plastic or composite guides help keep the timing chain aligned.
Over time, the guides can:
- Crack
- Wear through
- Break apart
- Separate from their mounting points
A broken guide can create excessive chain slack and may allow the chain to jump one or more teeth.
Pieces of damaged guide material may also collect in the oil pan or block the oil pickup.
4. Incorrect Mechanical Timing
P0008 may appear after engine repairs if the timing components were installed incorrectly.
Possible mistakes include:
- Camshaft sprocket installed one tooth off
- Crankshaft timing mark misaligned
- Camshaft phaser installed incorrectly
- Timing chain placed on the wrong colored links
- Incorrect tensioning procedure
- Engine rotated before tensioner release
- Wrong replacement parts
If P0008 appears immediately after timing-chain, cylinder-head or engine work, verify mechanical timing before replacing sensors.
5. Low Engine Oil Level
Variable valve timing and hydraulic chain tensioners depend on adequate oil pressure.
Low oil can cause:
- Delayed camshaft movement
- Weak chain tension
- Inconsistent phaser operation
- Timing noise
- Camshaft correlation faults
Always check the engine oil level before beginning advanced diagnosis.
6. Dirty or Incorrect Engine Oil
Oil that is too thick, contaminated or overdue for replacement may not flow properly through small variable valve timing passages.
Possible oil-related causes include:
- Sludge
- Wrong viscosity
- Fuel dilution
- Metal contamination
- Extended oil-change intervals
- Restricted oil passages
Using the manufacturer-specified oil viscosity is especially important on engines with hydraulic camshaft phasers.
7. Low Oil Pressure
Even when the oil level is correct, insufficient oil pressure can affect the timing system.
Possible causes include:
- Worn oil pump
- Restricted oil pickup
- Excessive bearing clearance
- Clogged oil passages
- Damaged oil-pressure control valve
- Internal oil leak
- Failed tensioner seal
Mechanical oil-pressure testing may be necessary if low pressure is suspected.
8. Faulty Variable Valve Timing Solenoid
The variable valve timing solenoid controls oil flow to the camshaft actuator.
A stuck or restricted solenoid may prevent the camshaft from reaching its commanded position.
Possible causes include:
- Sludge
- Metal debris
- Electrical failure
- Internal sticking
- Damaged screen
- Restricted oil passage
A faulty solenoid is generally less expensive to repair than a complete timing-chain failure, so it should be tested before major disassembly.
9. Failed Camshaft Phaser
The camshaft phaser adjusts camshaft timing based on oil pressure and ECM commands.
A worn phaser may:
- Stick advanced
- Stick retarded
- Move slowly
- Rattle during startup
- Fail to hold position
- Develop excessive internal play
A failed phaser can produce P0008 along with camshaft correlation or actuator performance codes.
10. Camshaft Position Sensor Problem
A faulty camshaft position sensor can provide an inaccurate signal to the ECM.
Possible sensor-related issues include:
- Internal sensor failure
- Metal debris on a magnetic sensor
- Damaged reluctor wheel
- Loose sensor
- Connector corrosion
- Wiring damage
However, P0008 is frequently caused by mechanical timing problems rather than the sensor itself.
11. Crankshaft Position Sensor Problem
The crankshaft position sensor provides the reference signal used to calculate engine timing.
A distorted or intermittent signal can create an apparent correlation fault.
Possible causes include:
- Sensor failure
- Damaged wiring
- Crankshaft reluctor damage
- Incorrect sensor air gap
- Loose reluctor wheel
- Connector contamination
A crankshaft sensor problem often causes additional codes, stalling or a no-start condition.
12. Damaged Reluctor Wheel
The camshaft or crankshaft reluctor wheel provides the timing pattern read by the position sensor.
A reluctor wheel may become:
- Loose
- Bent
- Cracked
- Misaligned
- Damaged during engine work
Some reluctor wheels are pressed onto the crankshaft or camshaft and can shift without being immediately visible.
13. Faulty ECM or PCM
A failed control module is possible but rare.
The ECM should only be suspected after verifying:
- Mechanical timing
- Oil level and pressure
- Sensor signals
- Wiring integrity
- VVT solenoid operation
- Camshaft actuator operation
- Reluctor alignment
How Serious Is the P0008 Code?
P0008 is a serious diagnostic code.
The engine may continue running, but the code can indicate significant mechanical timing wear.
Ignoring P0008 may lead to:
- Worsening timing-chain wear
- Chain jump
- Engine stalling
- No-start condition
- Valve-to-piston contact
- Bent valves
- Damaged pistons
- Cylinder-head damage
- Complete engine failure
The risk of internal damage is highest on interference engines, where the valves and pistons occupy the same physical space at different points in the combustion cycle.
If the timing chain jumps far enough, they may collide.
Can You Drive With P0008?
Limited driving may be possible if:
- The engine runs smoothly.
- No loud timing noise is present.
- Oil pressure is normal.
- The Check Engine Light is steady.
- No misfires are occurring.
- Power remains normal.
However, continued driving is not recommended until the cause is identified.
Stop driving immediately if you hear:
- Loud chain rattling
- Metallic knocking
- Repeated startup clatter
- Sudden loss of power
- Severe misfiring
- Backfiring
The vehicle should also be towed if the engine stalls, will not restart or displays a low-oil-pressure warning.
How to Diagnose P0008
Step 1: Scan for Additional Codes
Use an OBD-II scanner to check for related codes.
Common companion codes include:
- P0009
- P0010
- P0011
- P0012
- P0014
- P0016
- P0017
- P0018
- P0019
- Misfire codes
- Oil-pressure codes
Multiple camshaft correlation codes strongly suggest a mechanical timing or oil-pressure problem.
Record freeze-frame data before clearing anything.
Step 2: Check the Engine Oil
Inspect:
- Oil level
- Oil condition
- Oil viscosity
- Signs of sludge
- Metal particles
- Fuel contamination
- Coolant contamination
Correct an improper oil level and replace severely contaminated or incorrect oil.
An oil change may improve a sticking VVT system, but it will not repair a stretched timing chain.
Step 3: Listen for Timing Chain Noise
Start the engine from cold and listen near the timing cover.
Common warning sounds include:
- Brief startup rattle
- Continuous chain slapping
- Metallic ticking
- Rattle that changes with engine speed
A cold-start rattle often points toward a tensioner, guide or camshaft phaser problem.
Do not place hands, clothing or tools near moving belts and pulleys.
Step 4: Inspect Wiring and Connectors
Check the wiring for:
- Camshaft position sensors
- Crankshaft position sensor
- VVT solenoids
- Oil-pressure switches
- ECM connectors
Look for:
- Broken wires
- Corrosion
- Oil contamination
- Loose terminals
- Harness rubbing
- Heat damage
Repair visible electrical faults before mechanical disassembly.
Step 5: Compare Commanded and Actual Camshaft Position
A professional scan tool may display:
- Commanded camshaft angle
- Actual camshaft angle
- Camshaft phase error
- Crankshaft-to-camshaft correlation
- VVT solenoid duty cycle
A camshaft that consistently remains retarded may indicate:
- Chain stretch
- Weak tensioner
- Restricted oil flow
- Failed actuator
- Incorrect mechanical timing
A camshaft that moves erratically may suggest a phaser, oil-pressure or sensor-signal problem.
Step 6: Test the VVT Solenoids
Depending on the engine, the solenoids may be tested by:
- Measuring resistance
- Checking power and ground
- Commanding operation with a scan tool
- Inspecting screens for debris
- Temporarily swapping identical solenoids
- Applying fused power according to service procedures
Do not apply battery voltage directly unless the manufacturer’s procedure permits it.
Step 7: Check Oil Pressure
If the engine uses hydraulic chain tensioners or camshaft phasers, verify actual oil pressure using a mechanical gauge.
Compare readings at:
- Cold idle
- Warm idle
- Increased engine speed
Low oil pressure can affect multiple timing components simultaneously.
Step 8: Inspect Camshaft and Crankshaft Signals
An oscilloscope can display camshaft and crankshaft waveforms at the same time.
A trained technician can compare the waveform relationship with a known-good pattern to identify:
- Chain stretch
- Incorrect mechanical timing
- Sensor dropout
- Reluctor wheel movement
- Intermittent wiring faults
This can sometimes confirm a timing problem without removing the timing cover.
Step 9: Verify Mechanical Timing
If scan data or waveform analysis indicates a timing problem, inspect the engine mechanically.
This may require removing:
- Valve covers
- Front engine covers
- Access plugs
- Timing-chain guides
- Camshaft covers
Align the engine at top dead center and compare all timing marks with the service manual.
Check for:
- Chain slack
- Damaged guides
- Tensioner extension
- Worn sprockets
- Misaligned timing marks
- Loose phasers
Step 10: Check for Manufacturer Service Bulletins
Some engines have known timing-chain or camshaft actuator problems.
A Technical Service Bulletin may provide:
- Revised chain components
- Updated tensioners
- Revised oil recommendations
- New diagnostic limits
- ECM software updates
- Warranty extensions
- Special inspection procedures
Always check service information before major engine repairs.
Step 11: Clear the Code and Verify the Repair
After completing repairs:
- Clear all stored codes.
- Start the engine from cold.
- Listen for abnormal noise.
- Monitor actual and commanded camshaft position.
- Complete the required drive cycle.
- Rescan for pending codes.
- Verify that camshaft phase error remains within specification.
A successful repair should correct both the code and the underlying timing deviation.
Common P0008 Repairs and Costs
Repair cost varies significantly depending on whether the problem is oil-related, electrical or mechanical.
| Repair | Estimated cost |
| Diagnostic inspection | $100–$250 |
| Engine oil and filter change | $60–$180 |
| Repair sensor wiring | $100–$500 |
| Replace camshaft position sensor | $150–$400 |
| Replace crankshaft position sensor | $175–$500 |
| Replace VVT solenoid | $150–$500 |
| Replace camshaft phaser | $600–$1,800 |
| Replace timing-chain tensioner | $500–$1,500 |
| Replace timing chain, guides and tensioners | $1,200–$3,500 |
| Repair cylinder-head damage | $2,500–$6,000+ |
| Replace engine | $4,000–$12,000+ |
| ECM software update | $100–$300 |
| Replace and program ECM | $1,000–$2,500+ |
Timing-chain replacement is labor intensive because many engines require significant disassembly.
On some vehicles, the engine or transmission may need to be partially removed for access.
Common Diagnostic Mistakes
Replacing Sensors Without Checking Mechanical Timing
A camshaft position sensor may be named in related codes, but a stretched timing chain can produce an otherwise accurate sensor signal at the wrong time.
Replacing the sensor will not correct mechanical timing.
Assuming an Oil Change Will Fix Chain Stretch
Fresh oil can improve VVT operation and hydraulic tensioner response.
It cannot reverse physical wear in:
- Timing chains
- Guides
- Sprockets
- Phasers
If the chain has exceeded its allowable stretch, it must be replaced.
Ignoring Startup Rattle
A brief rattle may seem harmless, but it can indicate that the tensioner is losing pressure or the chain has excessive slack.
Startup noise should be investigated before the chain jumps.
Replacing Only the Chain
A complete timing repair may require:
- Chain
- Guides
- Tensioners
- Sprockets
- Camshaft phasers
- Seals
- One-time-use bolts
Installing a new chain with worn guides or sprockets can lead to an early repeat failure.
Failing to Check Oil Pressure
Low oil pressure can cause multiple timing-system components to malfunction.
Replacing the actuator or tensioner without correcting low pressure may not solve P0008.
Using Incorrect Timing Marks
Timing procedures can be complex, especially on dual-overhead-cam engines.
Always follow the manufacturer’s exact instructions and use required locking tools.
Clearing the Code Before Recording Data
Freeze-frame and camshaft-angle data may provide valuable clues.
Record the information before clearing the code.
Vehicles Commonly Affected by P0008
P0008 can appear on many vehicles, but it has historically been associated with certain engines that use long timing chains, multiple camshafts and hydraulic variable valve timing.
Potentially affected manufacturers include:
- Cadillac
- Chevrolet
- GMC
- Buick
- Saturn
- Holden
- Suzuki
- Ford
- Lincoln
- Mercedes-Benz
- Audi
- Volkswagen
- Nissan
- Infiniti
- Hyundai
- Kia
- Mazda
Vehicles that may encounter P0008 include models equipped with:
- V6 engines
- V8 engines
- Dual-overhead-cam engines
- Variable valve timing
- Hydraulic timing-chain tensioners
- Multi-chain timing systems
The code alone does not confirm that a specific model has a known defect. Diagnosis must be based on the exact engine, mileage, maintenance history and scan data.
How to Prevent P0008
Timing-chain and variable valve timing problems can often be reduced through proper engine maintenance.
Helpful preventive steps include:
- Check the oil level regularly.
- Use the manufacturer-specified oil viscosity.
- Use a quality oil filter.
- Avoid excessively long oil-change intervals.
- Repair oil leaks promptly.
- Investigate startup rattles early.
- Avoid driving with low oil pressure.
- Address misfires and rough running promptly.
- Keep VVT solenoids and oil passages clean.
- Use correct parts during timing repairs.
- Follow exact timing procedures.
- Replace related guides and tensioners when servicing the chain.
Oil maintenance is especially important because dirty or low oil can damage the chain, tensioners and camshaft actuators at the same time.
Frequently Asked Questions About P0008
What does code P0008 mean?
P0008 means the ECM has detected that the camshaft timing on Bank 1 does not match the expected crankshaft position.
Which side of the engine is Bank 1?
Bank 1 is the side of the engine that contains cylinder number one.
On an inline engine, the entire engine is considered Bank 1.
Is P0008 usually caused by a stretched timing chain?
A stretched timing chain is one of the most common causes, especially when P0008 appears with startup rattling or multiple camshaft correlation codes.
However, oil-pressure problems, camshaft phasers, VVT solenoids and sensor faults should also be checked.
Can low oil cause P0008?
Yes. Low oil can reduce pressure to the chain tensioners and variable valve timing system, causing incorrect camshaft position.
Can dirty oil cause P0008?
Yes. Sludge or incorrect oil viscosity can restrict the oil passages used by camshaft actuators and timing-chain tensioners.
Can a bad camshaft sensor cause P0008?
It is possible, but P0008 often points toward a mechanical timing or VVT performance problem rather than a simple sensor failure.
Can I drive with P0008?
Limited driving may be possible if the engine runs normally and makes no unusual noise, but continued driving is risky.
A loose or stretched timing chain may jump and cause serious engine damage.
Does P0008 mean the engine needs a new timing chain?
Not automatically.
The diagnosis should include oil condition, VVT operation, sensor signals, oil pressure and mechanical timing inspection.
However, chain replacement is common when excessive stretch is confirmed.
Can P0008 cause a no-start condition?
Yes. If the timing chain jumps or the crankshaft and camshaft signals become severely misaligned, the engine may crank without starting.
Can clearing the code fix P0008?
No. Clearing the code only resets the warning temporarily.
The code will return if the timing deviation remains.
How much does it cost to fix P0008?
Minor repairs such as an oil service or wiring repair may cost a few hundred dollars.
A complete timing-chain replacement can cost approximately $1,200 to $3,500 or more, depending on the engine and labor required.
Will P0008 fail an emissions test?
Yes. An active Check Engine Light or stored emissions-related powertrain fault will generally cause the vehicle to fail an OBD-based emissions inspection.
Final Thoughts
The P0008 code means the engine’s Bank 1 camshaft timing is no longer matching the expected crankshaft position.
The most common causes include:
- A stretched timing chain
- A failed chain tensioner
- Broken timing guides
- Incorrect mechanical timing
- Low or contaminated engine oil
- Low oil pressure
- A faulty VVT solenoid
- A worn camshaft phaser
- Camshaft or crankshaft sensor problems
Because P0008 may indicate significant timing-system wear, it should not be ignored.
Begin by checking the engine oil, related trouble codes, wiring and scan-tool camshaft data. If the camshaft timing remains outside specification, inspect oil pressure and mechanical timing before replacing sensors or control modules.
For more diagnostic guides, browse our growing OBD-II libraries:
- Complete OBD-II Code Library: https://my.prostreetonline.com/dtc-obdii/
- Body (B) Codes: https://my.prostreetonline.com/dtc-doctor/b-code-obd-ii-codes/
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