Lexus LS400 Intake Manifold Gaskets Replacement at your home or office.

How do mechanics replace the intake manifold gasket?

• Working on a cold engine, the engine cover is removed. If the intake manifold has internal cooling system passageways, the engine coolant is drained below the level of those passageways.
• The accelerator cable assembly and cruise control cable are removed and set aside. All electrical connections and emission and vacuum lines in the way of the intake are removed. Ignition components, such as the coil, are removed as needed. If the car has an upper plenum, that is removed and set aside.
• If the fuel rail is bolted to the intake manifold, the supply and return connections to the fuel rail are disconnected.
• Once all connections to the manifold are clear, the manifold is unbolted and removed from the engine.
• Aluminum and plastic manifolds are checked with a machinist’s straightedge to ensure the surface flatness does not exceed the original equipment manufacturer’s specification. If the surface of a manifold is not flat, the new gasket will not seal properly. Plastic manifolds are checked for cracks, heat damage, and warpage.
• Once the manifold is deemed re-usable or replaced as needed, the new gasket is applied, the manifold is put in position and the mounting bolts are torqued with a calibrated torque wrench in the OEM specified sequence. In some applications, RTV sealant must be applied in corners of the mounting surface or specified hard-to-seal spots, per the service manual.
• All removed components are then re-installed in the reverse of the above steps.
• Finally, the vehicle is run and checked for leaks, and test driven.