MerCruiser Intake Manifold Removal & Installation 5.0L 5.7L

MerCruiser Intake Manifold Removal & Installation 5.0L 5.7L

Removing, cleaning and installing a MerCruiser intake manifold, also termed inlet manifold, is a simple process. However, it’s highly recommended the mechanic download the factory repair manual when taking the manifold off, cleaning it, or when reinstalling it.

The repair manual contains critical data, such as torque specifications, torque patters and step-by-step removal, cleaning and installing procedures. It also contains special notes and warnings that the mechanic must abide by when removing, cleaning or installing the intake manifold.

The downloadable repair manual covers three main areas; intake manifold removal, intake manifold cleaning and inspection, and installation procedures.

MerCruiser Intake Manifold Removal & Installation 5.0L 5.7L (305-350)

Intake Manifold Removal

The manual discusses the steps in which the manifold should be removed. For example, it covers:

  • How to drain the engine cooling system.
  • How to disconnect houses from thermostat housing.
    How to disconnect the electrical leads that might interfere with the removal process.
  • How to disconnect the crankcase ventilation hoses from rocker arm covers.
  • How to disconnect the throttle cable from carburetor and how to remove the sight tube and fuel line running between the carburetor and fuel pump.
  • How to remove the distributor cap and where to mark the position of rotor on the distributor housing.

The manual also list other important details such as how to remove ignition components, remove the oil ending unit, and other miscellaneous items that will prevent the mechanic from removing the manifold.

Cleaning and Inspection

Cleaning and inspecting the MerCruiser intake manifold isn’t a complicated process but it should be a thorough process. The manual discusses how the mechanic should clean the cylinder head mating surface, how to inspect the manifold and which cleaning material the mechanic should use.

For example, the manual lists:

  • How to clean gasket materials from mating surfaces.
  • How to inspect the manifold for scratches and cracks.
  • How to clean intake passages of foreign material or varnish buildup.
  • How to position gaskets on cylinder heads.

The manual also list the type of sealant, how much should be used, and where the sealant should be applied before installing the manifold.


Reinstalling the MerCruiser intake manifold is the most complicated process. It requires careful placement, precise bolt tightness and the correct torque pattern. Installation instructions cover:

  • How to place intake on cylinder head.
  • Sealants required and special notes.
  • Intake manifold assembly torque specifications.
  • Intake manifold torque sequence.
  • How to install electrical leads, thermostat housing, fuel lines, etc.
  • How to adjust ignition timing and carburetor.
  • Inspecting for leaks and connections.

Downloading the repair manual is especially helpful because it includes illustrations of the engine and removal and installation process. For example, the manual uses illustrations that show the torque sequence, or what areas to apply sealant


    • We have a manual for that year and model. It covers MCM Alpha 5.0L, 5.0LX, 5.7L (4 barrel and 2 barrel), 5.7LX carb and EFI, 5.7L EFI and 350 Magnum and 350 Magnum EFI Gen+. The manual also covers MCM Bravo models, including 250 Magnum EFI/MP and 350 Magnum MPI Gen+.

      Manuals are available for all years between 1963 thru 1973, 1974 thru 1977, 1978 thru 1982, 1983 thru 1992, and 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 models.

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