Engines are unforgiving as many procedures need at least some special tools, this is more pronounced in the
Timing Chains where one has to be very careful not to damage the engine. Cylinder heads should be removed when the engine is cold to avoid warpage but one can take advantage of this by ensuring that the engine is sufficiently cool in this respect. To start the procedure you must purge fuel system pressure, remove the negative terminal of battery, and drain the cooling system. Depend the valve covers,
Intake Manifold and the
Exhaust Manifold and then proceed to pull out the timing chains, tensioners, sprockets and the
Camshafts. With the aid of a breaker bar, unscrew the cylinder head bolts in the correct procedure, lifting the cylinder head(s) from the engine and, if there is a problem, use wood and a hammer. Tin the aluminum cylinder head gasket sealing surfaces before installing the heads, and to remove a stuck head, you pry at the corners using a pry bar and this will not damage the sealing surface. The cylinder head gaskets should be pulled off the engines and the original positions should be taken into consideration as the gaskets are not to be interchanged. On reassembly, new cylinder head bolts have to be used to avoid leaks and damage, that are likely to occur in future. Make sure the mating surfaces of the cylinder heads and engine block are clean, and use only a gasket scraper or silicone gasket remover; do not use anything abrasive that could cause future leakages. Look for crack or any other defects on the mating surfaces and bottoms of the bolt holes; run a tap along the threads of bolt holes. Fit the new gaskets in place over the alignment dowels, fit the cylinder heads without disturbing the gaskets, and fit a new cylinder head bolts and tighten in a stage manner starting with the torque-angle technique. Last but not the least, reverse, do the final tightening, change the engine oil and filter, and fill the cooling system and start the engine and check for the leaks.