P0008 is a timing-related diagnostic trouble code that can make any driver nervous, and for good reason. It points to a problem with how your engine’s crankshaft and camshafts are lined up, which directly affects power, fuel economy, and long-term engine health. In this guide, you’ll learn what P0008 really means, the most common causes, and what symptoms to watch for before things get expensive. You’ll also see how a professional would diagnose it, realistic repair costs, and whether it’s safe to keep driving with this code stored.
What Does P0008 Mean?
P0008 stands for “Engine Position System Performance Bank 1.” In plain language, your engine computer (ECU/PCM) has detected that the relationship between the crankshaft and the camshaft(s) on bank 1 is out of the expected range. The ECU constantly compares actual camshaft position to where it should be based on crankshaft position and timing commands.
When the difference gets too large or doesn’t match the learned values, the ECU sets P0008. This usually points to timing chain stretch, a worn timing chain guide, a faulty camshaft actuator/phaser, or an issue with the cam/crank sensors or their signals.
Quick Reference
- Code: P0008 – Engine Position System Performance (Bank 1)
- Type: Powertrain, timing/cam-crank correlation
- Severity: Medium to high – can lead to engine damage if ignored
- Common Causes: Timing chain stretch, worn guides, faulty cam phaser, sensor issues
- Typical Symptoms: Check engine light, rough running, reduced power, poor fuel economy
Real-World Example / Field Notes
In the shop, I most often see P0008 on higher-mileage V6 engines, especially those with long timing chains. A typical case: a customer complains of a rough idle, poor acceleration, and a check engine light. Scan data shows P0008 and maybe a related camshaft position code. On teardown, the timing chain is stretched, guides are worn, and the tensioner is near its limit. After replacing the chain set, guides, and tensioner, the engine runs smoother, fuel trims normalize, and P0008 disappears for good.
Symptoms of P0008
- Check engine light on: The MIL/SES light will usually be illuminated and P0008 will be stored as a current or pending code.
- Rough idle: You may feel the engine shake at stoplights or notice an unstable idle RPM.
- Loss of power: Acceleration can feel weak, especially when merging or climbing hills.
- Poor fuel economy: Incorrect valve timing often leads to increased fuel consumption.
- Hard starting: Extended cranking or occasional no-start, particularly when hot, can occur.
- Rattling noise on cold start: A brief chain rattle from the front of the engine is common with worn chains or guides.
- Engine misfire or hesitation: You may feel surging, hesitation, or misfire codes along with P0008.
- Limp mode in severe cases: The ECU may limit power to protect the engine if timing is far out of range.
Common Causes of P0008
Most Common Causes
- Timing chain stretch: Over time, especially with poor oil maintenance, the timing chain can elongate. This changes the relationship between the crankshaft and camshaft positions and triggers P0008.
- Worn timing chain guides or tensioner: Plastic guides can wear or break, and hydraulic tensioners can stick or lose pressure. This allows chain slack and timing drift.
- Camshaft actuator/phaser problems: On variable valve timing (VVT) engines, a sticking or failed cam phaser can keep the camshaft in the wrong position relative to the crank.
- Incorrect timing after engine work: If the timing chain or belt was recently replaced and not timed correctly, the ECU will see a correlation error and set P0008.
- Low or dirty engine oil: VVT systems rely on clean oil and proper pressure. Sludge or low oil can affect cam phaser operation and cause timing errors.
Less Common Causes
- Faulty camshaft position sensor (Bank 1): A failing sensor can send inaccurate signals, making the ECU think timing is off when mechanical timing is fine.
- Faulty crankshaft position sensor: Similar to the cam sensor, a bad crank sensor can cause incorrect correlation data.
- Damaged tone ring/reluctor: A cracked or slipped reluctor wheel on the crank or camshaft can cause inconsistent position readings.
- ECU/PCM software issues: In some cases, a reflash or updated calibration is required to correct overly sensitive timing correlation thresholds.
- Wiring or connector problems: Corroded, loose, or damaged wiring to the cam/crank sensors can distort the signal and confuse the ECU.
Diagnosis: Step-by-Step Guide
Before you dive in, you’ll want a decent OBD-II scan tool (preferably one that shows live data and Mode $06), a basic hand tool set, a service manual or repair database, and ideally a mechanical timing locking kit for your specific engine. A digital multimeter can help with sensor and wiring checks.
- Confirm the code and check for companions: Scan the ECU for P0008 and any related codes (like camshaft position or VVT solenoid codes). Note freeze-frame data (RPM, load, temperature) when the code set.
- Visual inspection and oil check: Verify engine oil level and condition. Dark, sludgy oil or very low level is a red flag for VVT and chain issues. Inspect for oil leaks and listen for chain rattle on cold start.
- Check live data for cam/crank correlation: Using your scan tool, look at camshaft desired vs actual angle (Bank 1). Large differences at idle or under steady RPM suggest mechanical or VVT issues.
- Command VVT actuators (if possible): On advanced scan tools, you can command the cam phaser to advance/retard. If the commanded change doesn’t match the actual change, the phaser, oil supply, or control circuit may be at fault.
- Inspect cam and crank sensors: Check connectors for corrosion, oil intrusion, or broken locks. Use a multimeter or oscilloscope (if available) to verify sensor power, ground, and signal integrity.
- Check Mode $06 data: Some vehicles store detailed cam/crank correlation test results in Mode $06. Look for failed or borderline timing correlation tests on Bank 1.
- Mechanical timing verification: If data points to a mechanical issue, remove necessary covers and align the engine to TDC using factory marks. Confirm that cam and crank timing marks line up per the service manual. Any misalignment indicates chain stretch, skipped teeth, or incorrect installation.
- Inspect timing chain, guides, and tensioner: With covers off, check for excessive chain slack, worn or broken guides, and tensioner extension beyond spec. A heavily extended tensioner usually means the chain is stretched.
- Check for TSBs and software updates: Many manufacturers have technical service bulletins for P0008 on specific engines. A PCM reflash or updated parts kit may be recommended.
- Clear codes and road test: After repairs or inspections, clear the codes and perform a controlled road test. Monitor live data and see if P0008 returns under similar conditions.
Pro tip: If you’re already deep enough to inspect the timing chain on a high-mileage engine, it’s usually wise to replace the full timing set (chain, guides, tensioner, and related seals) rather than just one component. This minimizes the chance of a comeback repair.
Possible Fixes & Repair Costs
Fixing P0008 ranges from simple to complex depending on the root cause. At the low end, an oil change and cleaning or replacing a VVT solenoid might resolve minor correlation issues. Replacing a camshaft or crankshaft position sensor is usually straightforward. At the high end, a full timing chain set replacement can be labor-intensive and costly.
- Engine oil and filter change: $50–$150, especially if using high-quality synthetic oil and filter.
- VVT solenoid or cam phaser replacement: $200–$800 parts and labor, depending on engine layout and accessibility.
- Camshaft or crankshaft sensor replacement: $100–$350 installed.
- Timing chain, guides, and tensioner replacement: Commonly $800–$2,500+ depending on vehicle, engine type, and labor rates.
- ECU reflash or software update: $100–$250 at a dealer or well-equipped independent shop.
Typical repair cost ranges depend heavily on your vehicle, engine design, mileage, and local labor rates. Luxury or transverse V6 engines often cost more due to tight packaging and extra labor. Ignoring early signs usually pushes you toward the more expensive end of the spectrum.
Can I Still Drive With P0008?
You can often still drive with P0008 present, but it’s not a code you should ignore for long. If the engine is just slightly out of correlation, you may only notice a check engine light and mild performance issues. However, if the timing chain or guides are failing, continued driving can let the timing slip further, increasing the risk of valve-to-piston contact on interference engines. If you notice loud rattling, severe loss of power, or misfires, park the vehicle and have it towed to avoid catastrophic damage.
What Happens If You Ignore P0008?
Ignoring P0008 can turn a manageable timing repair into a full engine rebuild or replacement. As timing components wear further, you risk bent valves, damaged pistons, and broken guides circulating debris through the oil system. Fuel economy and drivability will continue to decline, and you may eventually face a no-start condition or a sudden engine failure at speed, which is both dangerous and expensive.
Related Codes
- P0027 – Exhaust Valve Control Solenoid Circuit Range/Performance Bank 1
- P0026 – Intake Valve Control Solenoid Circuit Range/Performance Bank 1
- P0019 – Crankshaft Position Camshaft Position Correlation Bank 2 Sensor B
- P0018 – Crankshaft Position Camshaft Position Correlation Bank 2 Sensor A
- P0017 – Crankshaft Position Camshaft Position Correlation Bank 1 Sensor B
- P0016 – Crankshaft Position Camshaft Position Correlation Bank 1 Sensor A
- P0009 – Engine Position System Performance Bank 2
- P0007 – Fuel Shutoff Valve “A” Control Circuit High
- P0006 – Fuel Shutoff Valve “A” Control Circuit Low
- P0005 – Fuel Shutoff Valve “A” Control Circuit/Open
Key Takeaways
- P0008 means your ECU has detected a timing correlation problem on Bank 1 between the crankshaft and camshaft(s).
- The most common causes are timing chain stretch, worn guides, faulty tensioners, and VVT/cam phaser issues.
- Symptoms range from a simple check engine light to rough running, poor fuel economy, and rattling noises.
- Driving for a short period may be possible, but long-term ignoring of P0008 can lead to serious engine damage.
- Proper diagnosis with a scan tool, live data, and sometimes mechanical inspection is crucial before replacing parts.
- Repair costs can vary widely, but catching the problem early usually saves you money and protects your engine.
Vehicles Commonly Affected by P0008
P0008 shows up most often on engines that use long timing chains and complex VVT systems. It’s especially common on certain GM V6 engines (such as 2.8L, 3.0L, 3.2L, and 3.6L “High Feature” V6s) found in Chevrolet, GMC, Cadillac, Buick, and Holden vehicles. Some Suzuki and Saab models that share GM powertrains are also affected. You may also see P0008 on various European and Asian V6 engines in SUVs, crossovers, and sedans where timing chain stretch is a known pattern failure.
FAQ
Can P0008 go away on its own?
P0008 rarely goes away on its own. You might clear the code and have it stay off for a while, but if the underlying timing or VVT issue is still there, the ECU will usually detect the fault again after a few drive cycles and turn the light back on.
Is P0008 always a bad timing chain?
No, P0008 is not always a bad timing chain, even though that’s a very common cause. It can also be triggered by worn guides, a sticking cam phaser, low oil pressure, faulty sensors, or wiring problems. Proper diagnosis is important before committing to a major timing repair.
Can low oil cause P0008?
Yes, low or dirty oil can contribute to P0008, especially on engines with VVT. The cam phasers and tensioners rely on oil pressure and clean oil to function correctly. If oil level is low or full of sludge, the timing system may not respond properly and the ECU can detect a correlation error.
How serious is P0008 compared to other engine codes?
P0008 is more serious than many basic emission-related codes because it deals directly with engine timing. While it may start as a drivability and efficiency issue, it can progress to severe mechanical damage if the timing chain or guides fail completely. It should be addressed sooner rather than later.
Can I clear P0008 and just keep driving?
You can clear P0008 with a scan tool, but that doesn’t fix the underlying problem. If the cause is mechanical wear or a failing component, the issue will remain and the code will likely return. Repeatedly clearing the code without repair can mask worsening symptoms until you’re facing a much more expensive repair or engine failure.