Intake Manifold Removal/Installation

Written by: Mike Ervin

The following steps are needed for intake manifold removal and installation.
 

Removal:
 

  • Disconnect the negative battery cable.
  • Drain the cooling system.
  • Remove the air cleaner assembly.
  • Remove A.I.R. crossover pipe.
  • Either remove the thermostat housing and the hose, or if the manifold is not being replaced, you may just disconnect the hose.  I recommend changing your thermostat either way.
  • Remove alternator upper bracket.
  • Disconnect the heater hose and disconnect all electrical connections and vacuum lines from the manifold.  Remove the EGR valve (if equipped).
  • On vehicles equipped with power brakes remove the vacuum line from the vacuum booster to the carburetor.
  • Move the air conditioning compressor to one side, if necessary.
  • Disconnect the fuel line to the carburetor or TBI unit.
  • Disconnect the carburetor linkage.
  • Disengage the electrical connections at the TBI unit, if necessary.
  • Remove the carburetor or TBI unit, if necessary.
  • Remove the intake manifold bolts.  Remove the manifold and the gaskets.


Installation:
 

  • Use a tap of the correct size to chase the threads in the intake bolt holes in the cylinder heads.  Mount each bolt in a vise run a die down the threads to remove corrosion and restore the threads.  Dirt, corrosion, sealant, and damaged threads will affect torque readings.
  • The mating surfaces of the intake manifold and the cylinder heads must be perfectly clean when the intake is installed.  I prefer to use RTV gasket sealant on the front and rear ridges of the block-to-manifold mating surfaces.  Run a solid 3/8-inch bead across and extending up on the head about 1/2-inch.  Don't let any of the RTV go into the lifter valley if you can help it.  Run a small bead on the head and the intake around the water jackets if your gaskets don't have a built-in bead.
  • Set the intake straight down in place without as much lateral movement as possible.
  • Coat the threads on the intake bolts with a good sealer, such as Permatex No.2.  This will keep oil from migrating up the threads out of the lifter valley.  Torque the intake manifold bolts to 30-35 ft. lbs. starting in the center and going in a criss-cross pattern, working your way to the outside.  I would do this in two steps of 20 and then the final 30-35 ft. lbs..
  • Reverse the removal procedure to complete installation.  Refer back to the distributor removal and installation procedure to help you install the distributor.

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