On the intake camshaft sprockets, do not dismantle VVTi assembly but shift it fully in or out, to effect its removal or installation, unscrew the center bolt of the camshaft. Bring the engine to TDC, pull the valve cover, and take the timing belt for 2.5L or 2.7L engines, and the 
Timing Chain for 3.3L engines. When reinstalling the cam sprockets and engine be positive that the two marks made with the sprockets face each other and that camshafts are not inter-changeable. Tighten the camshaft bearing cap bolts by 1/4 of a turn starting with the outer ones followed by the removal of the bearing caps and carefully pulling out the camshaft. Stack the bearing caps properly, if the valve hydraulic adjusters or lifters can be removed then do so and all the components should be laid neatly to be put back. Next, it is necessary to coat the lobes and bearing journals with camshaft installation lubricant, insert lash adjusters in their initial positions. For 2.5L and 2.7L engines, fit the timing chains astride the sprockets and adjust for the timing marks; in 3.3L engines, align each camshaft as it was before and check the position of the timing marks. Locate and orient the bearing caps sequentially with shaft arrows facing the direction of the drivebelt, gradually tighten bolt in a 1/4 turn along with reaching the torque value. Change camshaft oil seal if required, then replace the other parts in reverse order to the present step, be sure the all timing marks match and you do not want to suffer major engine breakdown. As with any automobile, to ensure that there are no leaks and that everything is in proper working order always start the engine, however valve train noise may linger for a while in older models. For checking valve clearance, twist off the valve cover, position the number one cylinder at TDC on the compression stroke side and then using a feeler gauge, check the clearance of the camshaft lobes to the respective lifters. To measure the remaining valves' clearances, rotate the engine one turn clockwise; if any clearances are beyond the limits, remove the camshaft(s) and lifters and measure the thickness of the lifter head and determine correct thickness for replacement lifters. Obtain the correct thickness lifters from the dealer and after fitting check on the clearance measurements to see if they are standard.