GM Camaro 1967-1981 Repair Guide

Intake Manifold

Print

REMOVAL & INSTALLATION



230 and 250 cid Engines

1975 and later L6 engines are equipped with an intake manifold which is integral with the cylinder head.

  1. Remove the air cleaner.
  2.  
  3. Disconnect the throttle rods at the bellcrank and remove the throttle return spring.
  4.  
  5. Disconnect the fuel and vacuum lines from the carburetor.
  6.  
  7. Disconnect the crankcase ventilation hose from the valve cover and the evaporation control hose from the carbon canister.
  8.  
  9. Disconnect the exhaust pipe from the manifold and throw away the packing.
  10.  
  11. Remove the manifold assembly and scrape off the gaskets.
  12.  
  13. Check the condition of the manifold. If the manifold is cracked or distorted 0.030 in. or more, it should be replaced to prevent exhaust leakage. To detect distortion, lay a straightedge along the length of the exhaust port faces. If, at any point, a gap of 0.030 in. or more exists between the straightedge and the manifold, the manifold should be replaced.
  14.  
  15. By removing one bolt and two nuts, the manifold can be separated.
  16.  
  17. To install, reverse the removal procedure, using new gaskets. Replace the exhaust pipe packing.
  18.  

Except 230, 231 and 250 cid Engines

See Figures 1 through 11



Click image to see an enlarged view

Fig. Fig. 1: Intake manifold seal locations for 229 cid V6 engines



Click image to see an enlarged view

Fig. Fig. 2: Make sure the intake manifold mounting bolts are tightened following the sequence shown to ensure proper sealing-229 cid V6 and small block V8 engines



Click image to see an enlarged view

Fig. Fig. 3: The intake manifold tightening sequence should be followed exactly, otherwise the manifold may not seal-big block (396 and 402 cid) engines



Click image to see an enlarged view

Fig. Fig. 4: The manifold can be removed with or without (shown) the carburetor installed-first detach all vacuum hoses from the manifold ...



Click image to see an enlarged view

Fig. Fig. 5: ... including the PCV hose



Click image to see an enlarged view

Fig. Fig. 6: Loosen the upper radiator hose clamp and remove the hose from the thermostat housing ...



Click image to see an enlarged view

Fig. Fig. 7: ... also detach the heater hose from the manifold



Click image to see an enlarged view

Fig. Fig. 8: Remove the alternator upper bracket ...



Click image to see an enlarged view

Fig. Fig. 9: ... and position the throttle linkage bracket aside



Click image to see an enlarged view

Fig. Fig. 10: Remove all of the intake manifold mounting bolts ...



Click image to see an enlarged view

Fig. Fig. 11: ... then finally, lift the intake manifold off the engine block and cylinder heads-small block V8 shown

  1. Remove the air cleaner.
  2.  
  3. Drain the radiator.
  4.  
  5. Disconnect:
    1. Battery cables at the battery.
    2.  
    3. Upper radiator and heater hoses at the manifold.
    4.  
    5. Crankcase ventilation hoses as required.
    6.  
    7. Fuel line at the carburetor.
    8.  
    9. Accelerator linkage.
    10.  
    11. Vacuum hose at the distributor.
    12.  
    13. Power brake hose at the carburetor base or manifold, if applicable.
    14.  
    15. Ignition coil and temperature sending switch wires.
    16.  
    17. Waterpump bypass at the water pump (Mark IV only).
    18.  

  6.  
  7. Remove the distributor cap and scribe the rotor position relative to the distributor body.
  8.  
  9. Remove the distributor.
  10.  
  11. If applicable, remove the alternator upper bracket. As required, remove the oil filler bracket, air cleaner bracket, air conditioning compressor and bracket, and accelerator bellcrank.
  12.  
  13. Remove the manifold-to-head attaching bolts, then remove the manifold and carburetor as an assembly.
  14.  
  15. If the manifold is to be replaced, transfer the carburetor (and mounting studs), water outlet and thermostat (use a new gasket) heater hose adapter, EGR valve (use new gasket) and, if applicable, TVS switch and the choke coil. 1975-79 engines use a new carburetor heat choke tube which must be transferred to a new manifold.
  16.  

To install:
  1. Before installing the manifold, thoroughly clean the gasket and seal surfaces of the cylinder heads and manifold.
  2.  
  3. Install the manifold end seals, folding the tabs if applicable, and the manifold/head gaskets, using a sealing compound around the water passages.
  4.  

1974-75 350 V8 engines require a new intake manifold side gasket on 4-bbl engines. The new gasket has restricted cross-over ports. The 350 2-bbl uses a restricted cross-over gasket on the right-hand side and an open gasket on the left. The 350 4-bbl uses restricted cross-over gaskets on both sides. The correct gaskets are essential.

  1. When installing the manifold, care should be taken not to dislocate the end seals. It is helpful to use a pilot in the distributor opening. Tighten the manifold bolts to 30 ft. lbs. in the sequence illustrated.
  2.  
  3. Install the ignition coil.
  4.  
  5. Install the distributor with the rotor in its original location as indicated by the scribe line. If the engine has been disturbed, refer to "Distributor Removal and Installation" at the beginning of this section.
  6.  
  7. If applicable, install the alternator upper bracket and adjust the belt tension.
  8.  
  9. The remainder of installation is the reverse of the removal procedure.
  10.  
  11. Fill the cooling system, start the engine, check for leaks, adjust the ignition timing and carburetor idle speed and mixture.
  12.  

231 cid Engine

See Figure 12



Click image to see an enlarged view

Fig. Fig. 12: The intake manifold tightening sequence for the 231 cid V6 is only slightly different from the other engines, but should be followed exactly none-the-less

A Torx socket is necessary to remove the left front intake manifold bolt.

  1. Disconnect the battery and drain the cooling system. Remove the upper radiator hose, and the coolant bypass hose from the manifold.
  2.  
  3. Remove the air cleaner. Disconnect the throttle linkage from the carburetor. Remove the linkage bracket from the manifold. If the car is equipped with an automatic transmission, remove the downshift linkage.
  4.  
  5. Disconnect the fuel line from the carburetor. If equipped with power brakes, disconnect the power brake line from the manifold. Disconnect the choke pipe and all vacuum lines. Disconnect the anti-dieseling solenoid wire.
  6.  
  7. Remove the manifold bolts. It will be necessary to remove the distributor cap and rotor to gain access to the front left manifold torx bolt. Remove the plug wires from the plugs.
  8.  
  9. Remove the manifold.
  10.  
  11. Installation is in the reverse order of removal. Use a new gasket and seals. Coat the ends of the seals with a non-hardening silicone sealer. The pointed end of the seal should be a snug fit against the block and head. When installing the manifold, start with the center bolts (numbers one and two) and slowly tighten them until [cf2]snug. Continue with the rest of the bolts in sequence, tightening them in several stages to the correct torque.
  12.  

 
label.common.footer.alt.autozoneLogo