Pontiac 19205381 Cylinder Head <Use 6A2 X0019>

Before removing the cylinder head, turn the ignition off and lessen the fuel system pressure and unplug the negative terminal of the battery. Deracom the engine cooling jackets and then the alternator, valve cover, throttle body, fuel injectors, fuel rail, intake manifold and exhaust manifold-detaching the oxygen sensor if the cylinder head is divorced from its exhaust manifold. Next, take off the timing chain/sprockets, then the camshafts and lifters.Finally, you will also need to take out the pistons from the engine block. Unbolt the variable valve timing control valve and filter, label the coolant hoses, tubes and electrical connections that belong to the cylinder head and then unbolt them, unfasten the cylinder head bolts by turning them in a 90 degree angle but in the reverse of the sequence that was followed in tightening to avoid warping or cracking of the cylinder head. Raise the cylinder head off the engine block, using a screwdriver, if it is stuck, and strip out any remaining external parts, clean and inspect thoroughly. When installing, the mating surfaces of cylinder head and block must be slick and free of any debris; using only a gasket scraper made of plastic, and cleaning them with lacquer thinner or acetone. Make sure that the mating surfaces do not have nicks or deep scratches; if there are slight ones, use a file to remedy the situation, if they are severe, then it would be best to machine it. Run the threads of the cylinder head bolt holes by a tap and blow with compressed air. The head bolts must be new if the head is reinstalled, and the new gasket must be located over the dowel pins with the mark "Lot #" up and the cylinder head must be put on the block gently without shifting the gasket. Coat a thin film of clean engine oil over the threads and under the bolt heads and fit the bolt to the nut, screw each of bit tighten by hand. Tighten it in 3 stages more with the final stage involving an additional 90 degrees turning of the bolts. The remaining step of adopting installation is the reverse of the step of removing them, then the step of inspecting and readjustment of the check valves, if needed, the step of replacing the engine oil and oil filter, the step of refilling the cooling system, and lastly the step of running the engine to test for leaks.