GM 22503678 Engine Exhaust Manifold

Specific steps and precautions should be followed when dealing with exhaust manifold removal and installation for different engine types. First, remove the nuts from the manifold studs to disconnect the exhaust pipe or crossover pipe, pulling the flanged portion away through a collar sliding over, occasionally needing to loosen the crossover pipe on the other side to clear it. Hot air shrouds, accessory brackets and sometimes even steering shafts of some vehicles are among parts that obstruct access and should be removed. Also, unplug oxygen sensor if available. Bend back any locking tabs on the mounting nuts, soak them in solvent to loosen them, then remove them allowing removal of the manifold and seal. The surface of the block must be fully cleaned. For 196, 231, 252 and 350 Buick Engines, raise car; disconnect exhaust crossover pipe; remove various components depending on which side you are working on. The manifold can be removed once the bolts attaching it to cylinder heads are detached. The installation follows in reverse order using lockbolts. Exhaust manifold removal in left side for 305 and 350 Chevrolet Engines involves disconnecting exhaust pipe among other things while removing right side requires removing right front wheel for access. Assemble by replacing new gasket on manifold and doing up bolts in specified sequence. Removal of exhaust pipes is part of this process as well as unbolted exhaust manifolds plus hot air shrouds among others for 350 and 403 Oldsmobile Gasoline Engines. Re-installation is done in reverse order of removal. Steps include draining cooling system, removing air cleaner; disconnecting hoses & lines; removing manifolds & adapter seal for 263 & 350 Oldsmobile Diesel Engines. Install gaskets using sealers after thoroughly cleaning gasket surfaces. Bolts should be tightened to specified torques so that they do not leak out later during operation of the engines or while driving these cars hence becoming hazardous to the users. Disconnect exhaust pipes, remove manifold bolts and clean gasket surfaces for 265 & 301 Pontiac Engines both left and right sides. New gaskets should be used during the installation and bolts tightened uniformly. Left-side removal requires certain steps including prying bolt locking tabs, unclamping the exhaust pipe and disconnecting intermediate steering shaft for the 1986-87 Oldsmobile 307 Engine. Right-side removal necessitates disconnecting oxygen sensor lead and removal of crossover pipe. Secure bolts in stages upon cleaning gasket surfaces among other things while installing them. In all cases, proper torque and sealing procedures should be followed to prevent leaks, and any sensors or components removed during the process should be reinstalled correctly.

Install the carburetor heat stove pipe from the old manifold.

Install the manifold, torque-tightening the center bolts first, followed by the end bolts, and consider installing the left rear spark plug heat shield first due to inaccessibility after the exhaust manifold is in place.

Remove the brackets attached to the left side manifold, then disconnect the exhaust pipes from the manifold flanges, hanging them from the frame using wire.

Install the remaining components in the reverse order of removal, using a new gasket or packing at the exhaust manifold or crossover pipe flange.

1. Disconnect the battery. 2. Remove the air cleaner assembly. 3. Disconnect the hot-air pipe to the manifold. 4. Remove the hot-air shroud around the manifold. 5. Raise the car and support it firmly on jack stands. 6. Bend back the metal retainers around each manifold bolt head. 7. Remove each of the bolts. 8. Disconnect the exhaust pipe from the manifold, using penetrating oil if the fasteners are 'frozen' in place. 9. Remove the flywheel lower cover and the starter brace, wiring, and starter. 10. Remove the exhaust manifold from under the car.

Reinstall the remaining components in the reverse order of removal, ensuring to use a new gasket or packing at the crossover pipe flange.