P0008
PowertrainEngine Position System Performance Bank 1
The ECU tracks where the crankshaft is sitting and where the camshaft on Bank 1 is sitting, using the position sensors, and it expects them to line up within a tight tolerance. When those two signals drift out of step beyond what's allowed, it logs P0008. For you that usually means the engine timing has slipped, most often because a timing chain has stretched and the slack has thrown the cam timing off relative to the crank.
ⓘ Information only. This page provides general educational information about fault code P0008. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0008 mean?
P0008 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Engine Position System Performance Bank 1.
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on the dash, sometimes with the car dropping into limp mode
- • Rough idle and a stumble or hesitation when you pull away
- • Noticeably down on power, feels flat and lazy under throttle
- • Hard starting, particularly first thing on a cold morning
- • A rattle or chatter from the front of the engine on cold start that settles after a few seconds, classic stretched chain noise
- • Fuel economy creeping up on the brim-to-brim figure
Possible causes
Causes commonly associated with P0008, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Stretched timing chain that has lost tension, by far the usual cause on higher-mileage engines. As the chain wears the cam timing retards and the ECU spots the offset
- 2. Worn or sticking chain tensioner, or broken plastic guides, letting the chain flap and the timing wander
- 3. Faulty crankshaft or camshaft position sensor reporting a bad signal, the timing is actually fine but the data isn't
- 4. Oil contamination or low oil level upsetting the variable valve timing actuators, which the ECU reads as a position error
- 5. Damaged wiring or a corroded connector at one of the position sensors, often from heat or oil ingress
- 6. Slipped or cracked reluctor ring on the crank, so the crank signal itself is off
- 7. Failed ECM, rare, only consider this once everything physical checks out
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Scan the car and read the freeze frame, then check oil level and condition before anything else. Low or sludgy oil starves the VVT system and is the cheapest thing to rule out
- 2. Check the cam and crank sensor connectors and wiring for oil contamination, corrosion, or chafing. A poor connection mimics a timing fault perfectly
- 3. Live-data the camshaft and crankshaft correlation while cranking and running, and watch the cam timing angle. A large fixed offset points at the chain, an erratic reading points at a sensor
- 4. Back-probe the sensor outputs with a scope to confirm clean signals against the manual figures before condemning a sensor
- 5. If sensors and oil are sound, listen for chain rattle on cold start and inspect the chain, tensioner, and guides for stretch and wear. This may mean pulling the timing cover
Common questions about P0008
What's the actual risk if I just keep driving on it? +
If the cause is a stretched chain, the danger is the chain jumping a tooth or the tensioner letting go. On an interference engine the pistons and valves meet, and you're looking at a bent valve job or a scrapped engine. If it turns out to be a duff sensor, the car runs fine and there's no mechanical risk. The problem is you don't know which until it's diagnosed, so treat it as serious until proven otherwise.
How quickly do I need to deal with this? +
Soon. Get it scanned and the oil checked within days, not weeks. If you've got the cold-start rattle as well as the code, stop driving it any more than you have to and get it on a ramp. A timing failure can happen on the next start. If it's clearly just a sensor and the engine runs clean, it's less urgent, but I still wouldn't sit on it for months.
Is it the sensor itself or could it just be the wiring? +
Both are real possibilities and they get mixed up all the time. The connectors on these sensors sit in a hot, oily spot and they corrode or get oil-fouled, which throws the same code as a dead sensor. Always inspect the plug and the harness before you order a part. A wiggle test on the connector with live data running often catches an intermittent that a static check misses.
How long is the job once they know what it is? +
A position sensor swap is usually an hour or so depending on access, some are awkward to get at on a packed engine bay. A timing chain, tensioner, and guide set is a different animal, typically half a day to a full day of labour because the front of the engine has to come apart. On something like a GM 3.6 V6 that has known chain issues it can run into four figures by the time you've paid main dealer labour and parts.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →