GM 12566671
Camshaft

The left Camshaft replacement requires uninstalling both Intake Manifold levels followed by removal of the left bank Camshaft cover together with sensors and position actuator solenoid. Obtain the Crankshaft rotation socket (EN46111) to rotate the Crankshaft until both camshafts achieve neutral (low tension) position while their flats remain parallel to the Camshaft cover rail. An open-end wrench positioned at the Camshaft hex will prevent Camshaft/engine rotation but leave the Camshaft position actuator bolt untouched until further steps are completed. The Timing Chain retention tool (EN46108) must be inserted fully into both Timing Chain segments for retention before tightnening its nuts. Mark the Timing Chain and its corresponding positions on the Camshaft position actuators for correct assembly before taking out the Camshaft position actuator bolt and camshafts. The installation process requires both components to align their designated reference marks before leaving the Camshaft position actuator bolt unwrapped. After mounting the camshafts onto their respective locations in the cylinder head you should install the Camshaft position actuators onto the camshafts and afterwards place the camshafts and Camshaft bearing caps. After removing en46108 install an open-end wrench at the Camshaft hex to stop its rotation before you install and tighten the Camshaft position actuators. Install the intake Camshaft position actuator solenoid with Camshaft sensors as well as the Crankshaft balancer and Camshaft cover and upper Intake Manifold and lower Intake Manifold.

Start at the upper Intake Manifold, and remove it along with the lower Intake Manifold; remove the Camshaft covers, Camshaft sensors, and the intake Camshaft position actuator solenoid. Next, withdraw the Crankshaft balancer and rotate the Crankshaft using Crankshaft rotation socket (EN 46111) until both the camshafts are in a neutral position, thus Camshaft flats are parallel with the Camshaft cover rail. In the Camshaft, use an open end wrench at the hex to prevent rotation and loosen the Camshaft position actuator bolt without removing. The Timing Chain retention tool (EN 46108) fully engaged into the Timing Chain and the en 46108 nuts are firmly tightened. Mark the Timing Chain and Camshaft position actuators to assemble them correctly and then remove the Camshaft position actuator bolt and the Camshaft bearing caps together with the Camshaft. For installation, align the Camshaft position actuators marks and position the camshafts to the Cylinder Head and assemble them on Camshaft actuators. Mount the camshafts and the Camshaft bearing caps, remove the en 46108 and replace the Crankshaft balancer. Use the open-end wrench for no further rotation when inserting and tightening the Camshaft position actuators, intake Camshaft position solenoid, the Camshaft sensors, and Camshaft cover, and eventually, the upper and lower Intake Manifold.

The left side Camshaft replacement process begins with removing the upper Intake Manifold with lower Intake Manifold while proceeding to the left bank Camshaft cover followed by Camshaft sensors and Camshaft position actuator solenoid and Crankshaft balancer. Exclusive usage of Crankshaft rotation socket (EN 46111) enables Crankshaft rotation until camshafts reach neutral position where flats become parallel with Camshaft cover rail. Do not remove the Camshaft position actuator bolt now but loosen it while using an open-end wrench at the Camshaft hex to prevent engine rotation. Extend the Timing Chain retention tool (EN 46108) completely into the Timing Chain while securely tightening its nuts until the Camshaft Timing Chain along with the Camshaft position actuators exhibit proper assembly indicators. Follow this procedure to mark the Timing Chain and respective locations on the Camshaft position actuators before you uninstall the Camshaft position actuator bolt and the camshafts. You must maintain the following alignment of marks between the Camshaft position actuator and Timing Chain before moving on without screwing the Camshaft position actuator bolt. Mount the camshafts within the cylinder head after adding Camshaft actuators and move forward with Camshaft bearing caps installation. Use the open-end wrench at the Camshaft hex to prevent rotation before removing the Timing Chain retention tool (EN 46108). First, install and securely tighten the Camshaft position actuators before adding the intake Camshaft position actuator solenoid along with Camshaft sensors and Crankshaft balancer and Camshaft cover and lastly install the upper Intake Manifold with the lower Intake Manifold.

Remove the Timing Chain Retention Tool (EN 46108) and use an open-end wrench at the camshaft hex to prevent rotation while installing and tightening the camshaft position actuators.

Insert it between the camshaft actuators, ensuring the bottom line of the tool is adjacent to the top surface of the cylinder head.

Loosen the camshaft position actuator bolt without removing it.

Alternately loosen the camshaft bearing cap bolts a few turns at a time using the specified loosening sequence.

Ensure the intake and exhaust camshafts are properly identified by their respective stamps.

They are correctly timed when the crank sprocket and the intermediate shaft sprocket have their timing marks aligned, and all four camshaft position actuator timing marks are perpendicular (90°) to the cylinder head deck surface at the top of their rotation.

Install the camshaft intermediate drive shaft retaining bolts, tightening them to 10 Nm (89 inch lbs.).

Remove the camshaft position actuator bolt, camshaft bearing caps, and the camshaft.

Install the intake camshaft position actuator solenoid, camshaft sensors, crankshaft balancer, camshaft cover, and the upper intake manifold with the lower intake manifold.

Remove the upper intake manifold along with the lower intake manifold.

First, remove the camshaft intermediate drive shaft sprocket.

Use the open-end wrench at the camshaft hex again to prevent rotation.

Do not tighten the camshaft position actuator bolt yet.

Ensure the tips of the Timing Chain Retention Tool (EN 46108) are fully engaged into the timing chain.