P0008 on GMC: How to Diagnose & Fix
Engine Position System Performance - Bank 1
2 GMC models · 2 documented issues · 2 critical · $1,800-$4,000 repair
P0008 on GMC by model: symptoms, diagnosis and fix
First-generation Terrains ordered with the optional V6 - the 3.0L LF1 in 2010-2012 and the 3.6L LFX from 2013-2017 - use GM's High Feature V6 architecture with four timing chains. The chains and their tensioners/guides stretch and wear prematurely, particularly on engines run on the oil-life monitor's long intervals or that have consumed oil between changes and starved the hydraulic tensioners. The ECM detects the resulting camshaft-to-crankshaft phase error and sets P0008 or P0009. This is a completely separate failure from the 2.4L Ecotec timing chain issue already documented: different engine family, different chain count, different repair.
Common Symptoms
- Check engine light with cam/crank correlation codes
- Rattle from the front of the engine on cold start
- Rough idle and reduced power
- Low oil level between changes
- Engine may crank but not start in severe cases
How to Fix
Confirm cam/crank correlation and oil-pressure/maintenance condition, then replace the primary and both secondary chains, guides, tensioners and sprockets as a set. Correct the oil-consumption or lubrication cause rather than clearing codes alone.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Cloyes 9-0753SWP timing-chain kit with sprockets and water pump$355
Direct listing supplies three chains, guides and tensioners; verify VIN/engine and confirm any seals, one-time fasteners and VVT components required separately.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
GM bulletin 12-06-01-009D covers 2007-2012 GMC Acadia vehicles with 3.6L High Feature V6 engines (RPO LY7 or LLT) and timing-chain correlation DTCs P0008, P0009, P0016, P0017, P0018 or P0019.
Common Symptoms
- Check-engine light
- Camshaft-to-crankshaft correlation DTC
How to Fix
Complete the GM diagnostic procedure before ordering parts. When a stretched timing chain is confirmed, use the applicable GM timing-chain kit. The bulletin says guides, sprockets, actuators and the crank gear should not be replaced automatically unless separately worn or diagnosed.
Sources for this issue (1)
P0008 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0008 mean on a GMC?
P0008 stands for "Engine Position System Performance - Bank 1." P0008 means the engine computer detected that Bank 1 of the engine is timed incorrectly relative to where it should be — specifically, the relationship between the crankshaft and camshaft positions on that bank is off. The 'Engine Position System' refers to the components (timing chain/belt, sprockets, tensioners, and the variable valve timing actuators) that keep the camshafts synchronized with the crankshaft. When the computer commands a timing position but the sensors report the bank is out of the expected range, it sets this code. It generally signals a mechanical timing problem on Bank 1 that can affect performance and, if severe, risk internal engine damage. On GMC it is documented across 2 models: Terrain, Acadia.
What are the most common causes of P0008?
The most common causes of P0008 are: Stretched or worn timing chain, Failed or worn timing chain guides or tensioner, Faulty camshaft position (VVT/VCT) actuator or solenoid, Low or dirty engine oil affecting timing actuator operation, Jumped or mistimed timing chain/belt after service, Faulty crankshaft or camshaft position sensor, Clogged oil control valve or oil passages. The specific cause varies by vehicle.
How much does it cost to fix P0008 on a GMC?
Published repair estimates on GMC range from $1,800 to $4,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0008 on a different make?
View P0008 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.