P0008 Code: Engine Position System Performance (Bank 1)
Camshaft timing on bank 1 has drifted from the crankshaft. Often a stretched timing chain.
At a glance
Severity: Moderate
- Meaning
- Engine Position System Performance (Bank 1)
- System
- Fuel & Air Metering · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $70–$8,000
- DIY difficulty
- Hard
P0008 means the engine computer has compared where the camshafts on bank 1 are with where the crankshaft says they should be, and found a lasting offset beyond what it can accept. Unlike P0016, which concerns one specific camshaft, P0008 describes the position system of the whole bank, so it tends to appear when every cam on that side has shifted by about the same amount. The classic cause is a stretched timing chain or a worn tensioner and guides, and it's closely associated with GM's 3.6-liter V6 and some GM four-cylinders, where oil neglect speeds up chain wear. Oil level and quality, a tensioner that bleeds down, a phaser problem or an incorrectly timed chain after a previous repair can produce the same result. Seen together with P0009 for bank 2, it points strongly at the primary chain.
Can I keep driving? Drive gently and only as far as needed. Chain stretch gets worse, and if the chain jumps a tooth or breaks on an interference engine, the valves can hit the pistons and the repair becomes an engine replacement.
How to read P0008
- P Powertrain
- 0 Generic (SAE)
- 0 Fuel/air & emissions (aux.)
- 08 Specific fault
Symptoms
- Check engine light, often with P0016 to P0019 or P0009 stored as well
- Brief rattle from the front of the engine for a few seconds on cold start
- Rough or uneven idle and slight hesitation
- Reduced power and worse fuel economy
- Longer cranking before the engine catches
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Stretched timing chain with worn guides and tensioner
- Low oil level, sludged oil or wrong viscosity starving the tensioner and phasers
- Chain installed one tooth off, or cams not locked correctly during an earlier repair
- Cam phaser sticking or its oil control solenoid not working correctly
- Camshaft or crankshaft sensor, wiring or reluctor ring problem
- Engine computer needs a software update or a cam/crank relearn
Diagnosis step by step
Check the oil before anything else
Pull the dipstick with the engine off on level ground. Low, dark or sludgy oil is both a cause and a warning sign; ask when the oil was last changed and whether the engine burns oil. Top up or change with the grade the manufacturer specifies before drawing any conclusions.
Tools: Flashlight
Read the full code pattern
Record every stored code and the freeze frame. P0008 alone points to bank 1; P0008 with P0009 suggests the primary chain that drives both banks. Codes such as P0010 to P0014 alongside it shift suspicion toward the variable valve timing control rather than the chain.
Tools: OBD-II scanner
Look at cam position deviation data
On GM vehicles, a capable scan tool shows a cam position variation value for each camshaft. At warm idle, all cams on bank 1 sitting off in the same direction by a similar amount is the signature of chain stretch, while one cam alone off points to its phaser or sensor.
Tools: OBD-II scanner
Listen at a true cold start
Let the car sit overnight and start it with the hood open. A rattle from the timing cover that lasts a few seconds, then fades as oil pressure builds, is typical of a tired tensioner and loose chain.
Rule out sensor and wiring faults
Inspect the cam and crank sensor connectors and wiring, and check for signal circuit codes. A sensor rarely causes P0008 on its own, but it's cheap to check and avoids blaming the chain for a wiring fault.
Tools: Multimeter, Flashlight
Confirm mechanically before ordering parts
Remove the valve cover or timing cover inspection points and look at chain slack, guide wear and tensioner extension, and check the timing marks against the service procedure. A chain job is a major repair, so make sure the diagnosis is solid first.
Tools: Torque wrench, Flashlight
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Oil and filter change with the approved oil grade | Yes | $70–$150 |
| Cam phaser oil control solenoid replacement | No | $150–$450 |
| Complete timing chain set, four-cylinder | No | $1,000–$2,000 |
| Complete timing chain set, V6 (primary and secondary chains) | No | $1,800–$3,500 |
| Engine repair or replacement after the chain has jumped | No | $3,500–$8,000 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Chevrolet
The 3.6-liter V6 used in models such as the Traverse, Equinox, Malibu, Impala and Camaro is well known for timing chain stretch that sets P0008 and P0009, usually with P0016 to P0019. Long oil change intervals and low oil level are a big factor. The fix is normally a complete chain, guide and tensioner set.
GMC
The Acadia and Terrain with the 3.6-liter V6 share the chain-stretch problem behind P0008 and P0009. The 2.4-liter four-cylinder in the Terrain can also stretch its chain, often after oil consumption has let the level run low.
Field data
| Chevrolet | 62 | ||
|---|---|---|---|
| GMC | 12 | Acadia |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P0008 turns on the check engine light, which fails an OBD-II emissions inspection. Clearing it won't last: the computer re-learns the cam offset and sets it again within a few drives.
Frequently asked questions
Will replacing the camshaft sensor fix P0008?
Rarely. P0008 means the cams on bank 1 are actually out of position relative to the crank, which a new sensor can't change. Check the sensor and wiring, but don't expect it to be the answer unless there's a separate sensor circuit code.
How long can I drive with P0008?
There's no safe mileage figure. Chain stretch progresses, and on an interference engine a chain that jumps or breaks lets valves strike the pistons. Keep the oil topped up, avoid hard acceleration and get it diagnosed soon.
Can an oil change clear P0008?
Sometimes, if the real problem was sludged or low oil affecting the tensioner or phasers. It won't shorten a stretched chain, though. If the code returns after fresh oil and a relearn, the chain is the likely culprit.
What's the difference between P0008 and P0016?
P0016 compares the crankshaft with one specific camshaft sensor. P0008 is a broader check of the whole engine position system on bank 1. They often appear together, and seeing both makes a mechanical timing problem more likely than a single bad component.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
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