When working on the timing belt or chain, the camshaft sprockets need to be detached; before doing this ensure that they are labeled for reassembly purposes. The camshaft bearing caps are each numbered using a single digit, while those for the exhaust are labeled from 0 to 4, and those for the intake side, from 5 to 9; when reinstalling the caps, the visible side has the number. Turn the camshaft bearing cap bolts in a turning pattern of half a turn to free pressure on the valve springs. Slide out the caps, remembering the marks and dowels, next extract the camshafts and oil seals and the intake camshaft, which has a reference lobe on it. Label the contents of sixteen small containers so that cam followers' bearings remain with shims, not to aggravate wear. Inspect both camshafts vertically as well as horizontally, and the cam followers as well, to look for any overt tapering or ovality, coupled with the normal wear and tear signs and signs of overheating. Take the diameter of each journal and inspect running clearance with Plastigage; if any bearing is worn beyond this, change the camshaft or the cylinder head if required. On installation, rotate the engine back from TDC to avoid valve knocking, apply oil to the cam follower bores and to the cam followers, and correct orientation must be done during instalment. New camshaft oil seals are to be placed and the bearings are lubricated before reversing the position of the camshafts while the bearing caps are to be sealed. Tighten the caps in sequence, putting them straight to the cylinder head, and cleaning unwanted sealant off. Before the final assembly, check brittle valve clearances by rotating the crankshaft to TDC and installer the timing pin. Replace camshaft sprockets loosely, continue the reassembly in the same way using the timing belt or chain and setting the valve clearances. Once the battery connection is re-established, let the Powertrain Control Module perform its idle and fuel trim procedure as it will work most effectively.
