Sierra 3500 4WD V8-6.0L (2008)
Camshaft: Description and Operation
Camshaft Position Actuator and Solenoid Valve Description
Camshaft
The camshaft is designed to provide a lubrication path for pressurized engine oil to flow to the camshaft position (CMP) actuator. Pressurized engine oil
enters the camshaft at bearing journal location number 2. Oil travels through the camshaft, out the front, and into the CMP actuator solenoid valve.
CMP Actuator Solenoid Valve
The CMP actuator solenoid valve consists of a housing, spool valve (1), spool return spring (2), oil filter (3), inlet check ball return spring (4), and inlet
check ball (5). Pressurized engine oil enters the valve and travels through the filter to the spool. Spool position is controlled by the CMP magnet and
engine control module (ECM). When the spool is moved to the proper position, oil flow is directed through the valve and into the CMP actuator
assembly. The CMP solenoid valve is a torque-to-yield design and should be replaced each time it is removed.
CMP Actuator Magnet