Before removing the cylinder head they require to relief the fuel system pressure and also to unplug the cable from the negative terminal of the battery. Suck the engine coolant then remove the intake and
Exhaust Manifolds and then the camshafts. Clean and disconnect the electrical connection and coolant hoses from the cylinder head noting that, in models namely 2006 and beyond, the water temperature control unit could be removed at this stage. To remove the cylinder head: first, turn the cylinder head bolts in an opposite sequence to the tightening pattern by turning them for 1/4 of a turn; next, to prevent both warping and cracking, lifting the cylinder head off of the engine block with a little pry. Withdraw any other accessories attached to the external casing in order to clean or examine it. Make sure to use a precision straightedge and run it across the gasket surfaces to see if they have warped as well as bulging and, to check for cracks and signs of coolant leakage. Before installing both the cylinder head and block, it is very important to clean the mating surfaces, using a gasket scraper together with brake cleaner. Inspect the areas of contact for flaws and remove any dirt that may be in the bolt holes. For each bolt steel threads on 2005 and earlier model year, clean the threads and check the length restrictively measure the bolt length and replaced any damage and exceed the limits of the length. For models produced after 2006, it is necessary to change all nuts used for the cylinder head bolts. Replace those elements to the cylinder head, align the new gasket properly and fit the cylinder head on the block over the gasket without shifting its position. Before engaging the nuts and bolts, spread clean engine oil on the threads and sub ports of the bolts heads, engage and tighten the nuts and bolts according to the sequence and following the additional 90 degrees turn required. The following are the procedures that are opposite to these removal steps; after that, there is a change of the engine oil and the oil filter, the coolant, starting of the engine and checking on the leakage.