To remove the
Timing Chain, tensioner, guides, and sprockets, first undo the three retaining bolts and carefully remove the closing plate from the left-hand end of the
Cylinder Head on the inlet camshaft side, taking care not to damage the mating surfaces. Next, remove the bearing cap housing that covers both camshafts by undoing three retaining bolts. Note the identification markings on the camshaft bearing caps for proper refitting, marking any unmarked caps to avoid incorrect installation. Gradually and evenly slacken the twenty remaining camshaft bearing cap retaining bolts to relieve valve spring pressure before fully unscrewing and removing the caps. Lift off the inlet and exhaust camshafts, noting their fitted positions, and use numbered containers to store each lash adjuster to prevent interchanging. If necessary, remove the variable valve timing control solenoids. For inspection, clean or renew the oil filter for the variable valve system, check the cam bearing surfaces and lobes for damage, measure camshaft run-out, and assess cam lobe height with a micrometer, replacing any damaged components. Verify camshaft bearing oil clearance and ensure proper positioning of bearing caps during refitting, tightening bolts to specified torque. Oil the lash adjuster bores and adjusters before carefully refitting them, ensuring correct orientation of the camshafts in the cylinder head. Clean mating surfaces thoroughly before reinstalling the bearing caps and tightening them in sequence. Clean the closing plate and apply sealant before refitting it and the timing chain, tensioner, guides, and sprockets, checking and adjusting valve clearances if the cylinder head or camshafts have been overhauled.