Mopar 4591862AG Plenum-Intake Manifold

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To remove the upper intake manifold, start by relieving the fuel system pressure and disconnecting the battery cable. Then, remove the air filter housing and label and disconnect the hoses and electrical connectors attached to the intake manifold and throttle body. Remove the bolts securing the EGR pipe and the brackets from the throttle body and upper intake manifold. Loosen the upper intake manifold bolts and lift the manifold from the engine. Clean the mounting surfaces and inspect the O-ring gasket. If it's in good condition, it can be reused. Install the gasket into the groove in the upper intake manifold and then install the manifold onto the lower intake manifold, tightening the bolts in a circular pattern.

After removing the lower intake manifold, clean and inspect the sealing surfaces and gaskets, replacing them if needed.

Position the lower intake manifold correctly over the cylinder heads and install the fuel rail and injectors. Tighten the bolts following the recommended sequence and torque.

Disconnect the brake booster vacuum hose, canister purge hose, and the PCV hose.

The mating surfaces of the cylinder heads and intake manifold must be perfectly clean when the manifold is installed, but don't use harsh chemicals or solvent on the plastic manifold, as it could become damaged.

To remove the lower intake manifold, drain the cooling system and remove the upper intake manifold. Label and detach any remaining hoses and remove the fuel rail and injectors. Remove the heater hoses and coolant hoses. Loosen the remaining manifold mounting bolts/nuts and carefully break the gasket seal. Turn the manifold over, replace the O-ring on the heater supply tube, and remove all traces of old gasket material and sealant. Clean the mating surfaces with lacquer thinner or acetone. Apply RTV sealant around the front and rear cylinder head water passages and lay the new gaskets in place. Position the manifold on the engine, aligning the gaskets and manifold with the ports in the cylinder heads. Install the fuel rail and injectors, then tighten the nuts/bolts following the recommended sequence. Refill the cooling system, run the engine, and check for leaks.

Remove the EGR pipe from the intake manifold.

After removing the lower intake manifold, clean and inspect the sealing surfaces and gaskets, replacing them if needed.

To remove the lower intake manifold, drain the cooling system and remove the upper intake manifold. Label and detach any remaining hoses and remove the fuel rail and injectors. Remove the heater hoses and coolant hoses. Loosen the remaining manifold mounting bolts/nuts and carefully break the gasket seal. Turn the manifold over, replace the O-ring on the heater supply tube, and remove all traces of old gasket material and sealant. Clean the mating surfaces with lacquer thinner or acetone. Apply RTV sealant around the front and rear cylinder head water passages and lay the new gaskets in place. Position the manifold on the engine, aligning the gaskets and manifold with the ports in the cylinder heads. Install the fuel rail and injectors, then tighten the nuts/bolts following the recommended sequence. Refill the cooling system, run the engine, and check for leaks.