– Incorrect timing chain
– Stretched timing chain
– Failed camshaft actuator or actuator solenoid
2007-2008 GMC Acadia
The service bulletin suggest replacing the primary drive and both secondary drive timing chains. Contact your GMC dealer for more information. The repair could still be cover under factory warranty.
The Engine Control Module (ECM) monitors the position of both camshafts and the crankshaft. The ECM performs a test for misalignment between both camshafts on one bank of the engine and the crankshaft. During the test the ECM learns the position of the camshafts and the crankshaft. While the engine is idling, the ECM compares the position of both the camshafts and the crankshaft with the learned value. The ECM will set the P0008 code if both learned values for one bank of the engine are exceeding a calibrated threshold in the same direction.