Repair Pontiac Mid-size 1974-1983 Repair Guide

Exhaust Manifold

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REMOVAL & INSTALLATION



1974 250 six and 1977-78 151 four-cylinder exhaust manifold removal and installation is covered under the "Intake Manifold" procedure (both manifolds are a unit).

1979 151 Four Cylinder Engine


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Fig. Fig. 1 Exhaust manifold mounting and bolt tightening sequence-1979 151 4-cylinder engine with separate manifolds

  1. Disconnect and remove the air cleaner assembly, including the carburetor, pre-heat tube.
  2.  
  3. Disconnect the exhaust pipe at the exhaust manifold. You will probably have to use a liquid rust penetrant to free the bolts.
  4.  
  5. Remove the engine oil dipstick bracket bolt.
  6.  
  7. Remove the exhaust manifold bolts and remove the manifold.
  8.  
  9. To install, mount the manifold on the cylinder head and start all bolts.
  10.  
  11. Tighten the bolts to specification using the torque sequence illustrated. Complete the installation by reversing the removal procedure.
  12.  

All V6 and V8 Engines


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Fig. Fig. 2 Typical V6 or V8 exhaust manifold mounting and hot air shroud mounting

Tab locks are used on the front and rear pairs of bolts on each exhaust manifold. When removing the bolts, straighten the tabs from beneath the car using a suitable tool. When installing the tab locks, bend the tabs against the sides of the bolt, not over the top of the bolt.

  1. Remove the air cleaner.
  2.  
  3. Remove the hot air shroud, (if so equipped).
  4.  
  5. Loosen the alternator and remove its lower bracket.
  6.  
  7. Jack up your car and support it with jack stands.
  8.  
  9. Disconnect the crossover pipe from both manifolds.
  10.  

On models with air conditioning it may be necessary to remove the compressor, and tie it out of the way. Do not disconnect the compressor lines.

  1. Remove the manifold bolts and remove the manifold(s). Some models have lock tabs on the front and rear manifold bolts which must be removed before removing the bolts. These tabs can be bent with a drift pin.
  2.  
  3. Installation is the reverse of the removal procedure.
  4.  



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Fig. Fig. 3 To remove the exhaust manifold, disconnect the exhaust crossover pipes from the manifolds

 
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