The camshaft should always be checked well for any signs of damage before it is fitted and the end play must, however, be checked before the removal of the camshaft. To discern cam lobe wear look at the lobe lift before pulling the camshaft out; remove the valve covers first and be sure that the number one piston is at top dead center on the compression stroke. Remove the lock nut underneath the
Rocker Arm and turn the rocker arm to the side to allow the use of the dial indicator which is fixed on the engine with the plunger on top of the first push rod. Rotate the crankshaft until the pointer of the dial indicator touches zero and then rotate the crankshaft slowly until the needle of the dial indicator withdraws reversing its direction and gets the maximum cam lobe lift. Do this for each valve and be sure that each piston is at the top dead center on the compression stroke. If the lobe lift is low compared to the specified values, the car requires a new camshaft to be fitted. On versions up to 2014, separate the intake manifold, rocker arms,
Pushrods,
Timing Chain, and camshaft sprocket, and then use the right tools to get the Lash Adjusters out and place them in the boxes that show their position for reinstallment. Camshaft and bearings should be checked for signs of wear, pitting, and any other sign of damage while checking the bearing journals with a micrometer. Remove and inspect conventional Lash Adjusters for wear, they should be slightly crowned; if any are depressed or badly worn, replace them with new Lash Adjusters and camshaft. Regarding roller Lash Adjusters, they should be checked for the ability to rotate smoothly to the surface of the cylinder bore and for excessive wear. Lubricate the camshaft and as for the installation; slide the camshaft into the engine and rotate it until the dowel pin is in the correct place. On 2018 and later models, before removing the camshaft and Lash Adjusters, the air conditioning system must be discharged and the fuel pressure reduced, the cooling system must be drained, and some components must be unbolted. Make sure that oil is put on the camshaft and Lash Adjusters when installing, align and snug torque the camshaft and Lash Adjusters and then bolt the rest in a reversal of the removal process. One must ensure the cooling system is full, the oil is new and must have changed the oil filter before starting the engine.