P0008 on Chevrolet: How to Diagnose & Fix

The 2.4L Ecotec in 2010-2017 Equinox is prone to premature timing-chain and balance-chain stretch, driven primarily by a collapsing chain tensioner and made worse by the engine's known oil-consumption problem (low oil reduces hydraulic pressure to the tensioner). Symptoms are a rattle at cold startup, a check-engine light, and rough running or loss of power. Because the engine is an interference design, a chain that skips timing far enough lets the valves contact the pistons, turning a maintenance item into an engine-destroying failure. GM issued Special Coverage Adjustment 12313 (10 years/120,000 miles) for 2010-2011 2.4L (LAF) engines because the chrome layer on the balance chain pins may wear and let the balance chain stretch; it covers the balance chain and fuel pump, not the timing chain.

GM's high-feature V6 in the Equinox suffers premature timing-chain stretch, distinct from the covered 2.4L chain issue. Worn chains/guides/tensioners throw off cam-to-crank timing, setting P0008/P0009 (engine position performance) and P0016-P0019 (crank/cam correlation). The classic symptom is a rattle or chain-slap on cold start from the front/passenger side of the engine. Long oil-change intervals and low oil accelerate the wear; left unfixed, a chain can jump time or break and bend valves.

The 3.6L high-feature V6 offered in the 2008-2012 Malibu — the LY7 for all of those years — uses three chains and plastic-faced tensioner shoes. The original chain and tensioner design wears prematurely, aggravated by GM's oil-life-monitor service intervals that let owners run 10,000+ miles on degraded oil. As the guides wear the chain goes slack, cam timing drifts out of the correlation window, and the ECM sets P0008 or P0016-P0019. Left alone the chain can skip a tooth on a cold start and the pistons will contact the valves. This is a different failure from the 2.4L four-cylinder chain issue: the V6 is a three-chain, rear-of-block-access design, the labor is far heavier, and the symptom onset is a rattle on cold start rather than the 2.4's oil-consumption-driven wear.

The 2.2L (L61) and 2.4L (LE5) Ecotec four-cylinders are prone to timing chain wear caused by failing plastic guides and weak tensioners, often aggravated by extended oil-change intervals or low oil. Because the engine is an interference design, a stretched chain that jumps time can let pistons strike valves and destroy the engine. The telltale sign is a rattling or scraping noise from the passenger side of the engine, especially on cold start, frequently accompanied by code P0008/P0017 for cam-to-crank correlation.

Worn (stretched) timing chains on the 3.6L High Feature V6 can set DTCs P0008, P0009, P0016, P0017, P0018 and/or P0019, and GM released timing chain service kits for the repair. Applies to: 2009-2012 Chevrolet Traverse with the 3.6L LLT V6 (GM bulletin 12-06-01-009F also lists other GM High Feature V6 models). GM's bulletin does not list 2013-2017 Traverse models.

On the Gen V 5.3L L83 (and 6.2L L86) in the Silverado 1500, the timing chain can stretch and the VVT cam phasers/actuators can wear, causing the camshaft to drift out of correlation with the crankshaft beyond what the variable-valve-timing system can correct. This sets crank/cam correlation and VVT codes, a startup rattle (slack chain before oil pressure builds), rough idle, reduced power, and on higher-mileage trucks a risk of the chain jumping. AFM operation and extended oil-change intervals accelerate the wear. It is a more involved repair than a sensor because it requires removing the front timing cover.

Gen V 5.3L engines use variable valve timing (VVT) with a cam phaser and VVT solenoid. Sludge and wear cause the phaser to rattle and the timing chain to stretch, producing a cold-start 'marbles in a can' rattle that often precedes a check-engine light. It sets crank/cam correlation codes (P0008/P0016/P0017) or VVT performance codes (P0011). GM PIP5258A covers P0011 cam actuator codes on the 5.3L L83 that persist after standard diagnosis, directing technicians to check oil pressure and the number 2 cam bearing that feeds the actuator. Ignored, a stretched chain can jump timing and cause severe internal damage.

The 3.6L direct-injected V6 used in fifth-generation Camaro is known for timing chain wear/stretch that can trigger cam/crank correlation faults, rough running, and reduced performance. GM issued service information and special coverage on related 3.6L timing chain concerns across multiple applications, and Camaro owners have documented the same issue in forums and complaints. Poor oil maintenance tends to accelerate wear because chain life is sensitive to lubrication quality and oil change intervals.