It is imperative that the engine be cold when removing the cylinder heads, in a bid not to have them warped. Cylinder head removal is one of the most complex procedures, which calls for several special tools, so, one has to prepare the tools in advance. Hence for models from 2003 and onward, it is advised that the engine be detached from the car during this operation. First of all, connect the negative battery terminal and remove its cable, and then drain the cooling system of the vehicle. After that, the valve covers and
Intake Manifold should be taken off, next the
Exhaust Manifolds and the cover of
Timing Chain. The cylinder heads can be removed still with the
Camshafts, the rocker arms as well as the lash adjusters in place but you have to clear the timing chains, and their respective tensioners and guides. Camshaft retaining fixtures should be used to secure the camshafts in position as the engine block is assembled. In case a cylinder head rebuild is to be performed, it is necessary to take off the rocker arms and camshafts. Tighten the cylinder head bolts a specified number of torques in reverse order with a breaker bar, and pry the gasket joint using a pry bar at the corners of the mating surface. Remove the cylinder head(s) of the engine by slightly lifting them up using a wood block and a hammer at the same time and place the head(s) on wood blocks so as not to dent. Lift off the cylinder head gaskets and pay attention to the fact that some of them are unique to their positions. During installation a new set of cylinder head bolts are required to avoid leakages in addition to damage on the car. The mating surfaces must be clean; they may be scraped lightly with a gasket scraper and wiped with a solvent; other parts of the engine should be covered to shield them from dirt. Inspect the access faces of the parts to be joined in order to look for any signs of damage that may be present after the previous process; complete the holes with a thread, turning them with a tap. SupPOSE that camshafts remain in the engine: place the new gaskets strictly over the alignment dowels and make sure that the camshafts are in the original TDC. Place the cylinder heads as not to damage the gaskets and put new cylinder head bolts then tighten the nuts in the right sequence by use of a torque wrench and a breaker bar coupled with a torque-angle shade. Lastly, perform the other remaining steps in the reverse order, replace the engine oil and filter, crank the engine and check for any sign of leakage.