Special tools are required for this procedure, so it is important to read through it before beginning work. Start by disconnecting the cable from the negative battery terminal, ensuring that the Theftlock audio system's lockout feature is turned off if applicable. Proceed to remove the timing chain and sprockets, followed by the timing chain housing-to-camshaft housing bolts, and then the ignition coil and module assembly. Disconnect the idle speed power steering pressure switch, remove the power steering pump and brackets, and take off the power steering pump drive pulley using a puller to avoid damage. Next, remove the oil/air separator as an assembly with the hoses attached, and set aside the fuel rail from the cylinder head. Unplug the oil pressure sending unit wire and unbolt the engine lifting bracket. Loosen the camshaft housing-to-cylinder head bolts in 1/4-turn increments, leaving two cover-to-housing bolts in place temporarily, then gently lift the housing off the cylinder head. Remove the two camshaft cover-to-housing bolts and push the cover off by threading four of the housing-to-head bolts into the tapped holes in the cover, carefully lifting the camshaft out of the housing. Clean the mating surfaces to remove old gasket material and oil, then remove and discard the oil seal from the intake camshaft. Store the Lash Adjusters in order, valve-side up, submerged in clean engine oil to minimize bleed-down. Inspect the camshaft and Lash Adjusters for wear and measure the Lash Adjuster bore and outside diameters, recording the results to determine clearance and compare to specifications for necessary replacements. For installation, use a new gasket to position the camshaft housing on the cylinder head, temporarily holding it with one bolt. Coat the camshaft journals, lobes, and Lash Adjusters with pre-lube, install them in their original locations, and lubricate the lip of the oil seal before positioning it on the camshaft journal. Install the camshaft with the sprocket dowel pin facing up, position the cover, and apply pipe sealant to the threads of the camshaft housing and cover bolts. Install new housing seals, the camshaft cover, and bolts while ensuring the oil seal is installed to the correct depth. Tighten the bolts in the specified sequence to the required torque and angle of rotation, then install the power steering pump pulley with a special tool. Reassemble the remaining parts in reverse order of removal, change the oil and filter, and follow the procedure to purge the Lash Adjusters of air if new Lash Adjusters were installed or if they bled down during disassembly. Finally, road test the vehicle and check for oil and coolant leaks.
Posted by GMPartsGiant Specialist 
