GM 12603753 Engine Exhaust Manifold

Before starting the process of removal of the front manifold, it is necessary to detach the cable from the negative terminal of battery. Following that, you should take off the heat shields from the manifold and the crossover pipe, and then disconnect the crossover pipe from the front exhaust manifold - you'll have to take off six bolts to remove the front exhaust manifold. Starting with the rear manifold first, the alteration of the rear manifold is done in the order of the removal of the alternation, the removal of the rear manifold oxygen sensor, the removal of the manifold heat shield and lastly the removal of the heat shield of the crossover pipe. Finally, un-bolt and take out the exhaust crossover pipe and unbolt the exhaust pipe with the rear manifold nuts. It may then be removed along with the gasket, and the surfaces will be scraped to remove any old gasket material taken on the manifold in the inspection of cracks and distortions. It is suggested that when warpage is checked, the manifold should be brought to an automotive machine shop for honing. take the exhaust manifold inner heat shield and gasket out then align the manifold with the head through the new heat shield and new gasket and install the bolts. Use the wrench or your hands to tighten the mounting bolting gradually from the central and clock wise round the bolts till they reach the recommended torque. Lastly, rebuild the remainder of the components and endeavor to commence the engine; prove if there are exhaust fumes between the manifold and the cylinder head as well as the manifold and the exhaust pipe.

Yes, if necessary, remove the exhaust manifold heat shield.

Finally, reinstall the remaining components in reverse order and start the engine to check for exhaust leaks between the manifold and cylinder head as well as between the manifold and exhaust pipe.

If needed, bend the exposed end of the exhaust manifold gasket back against the cylinder head.