If the camshafts have to be removed for any procedure, it is better to check the valve clearances prior to disassembly in order to order new lifters, if needed, from a dealership. Start with the timing chain removal-pay attention to the shape of the cam lobes of the no. 1 cylinder and slots in the ends of the camshafts. Disassemble the camshaft phaser and the sprockets that accompanies it with the help of an Allen wrench, and mark the parts that are to be reattached, with indelible ink. While holding the cam shaft in position, suspend the camshaft sprocket bolt just as much as necessary to allow loosening. Secondly there is need to, unsurprisingly, remove the Variable Camshaft Timing (VCT) solenoid fasteners and the front camshaft bearing cap bolts which lifts the cap off the two camshafts. Identify and indicate the bearing caps so that the right ones will be placed back in the correct position and with the correct orientation. Some of the camshaft bearing cap bolts may be extremely tight due to the pressure of the valve springs; as such, they can be removed progressively while loosening the tension of the springs, then remove the caps and take out the camshafts, noting that the exhaust camshaft has a reference lobe. It is important only to store each of the lifters in a clean container without swapping any of them. Look for worn out camshafts and lifters, check on the diameters of the lifters, and also look for signs of damages. If the engine contains loud noise at the valve components, setting the valve clearances could be called for. ScrollView the camshaft lobes and bearings for flatness and wear and measure the diameters of the journal. Measuring the bearing journal running clearance by Plastigage and if any clearance is beyond the service means, replace the camshaft or cylinder head. To get an indicator mark, clean those bearing surfaces and then to measure the camshaft endplay use a dial indicator. When installing ensure that the crankshaft is at the T DC; oil the lifter bores and the lifters and then place them back in their positions. Lubricate the camshaft bearing surfaces and then fit camshafts are to be in proper alignment. Remove all the dirt on the surfaces that are to be mated this is followed by application of RTV sealant on to the exhaust camshaft rear bearing cap. Place the camshaft bearing caps as indicated by the marked positions and then fasten them in the manner that was described above. Last, attach the variable camshaft timing solenoids, the phasers, the sprockets after which follows the reassembly of the timing chain, phaser and the re-timing of the valves, before fitting the valve cover the valve clearances should also be checked.
