GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 HHR 🢒 Engine 🢒 Engine Mechanical - 2.4L 🢒 Exhaust Manifold Cleaning and Inspection

    Object Number: 1594342 Size: SH

    Important: 

       • Do not reuse the exhaust manifold-to-cylinder head gaskets. Upon installation of the exhaust manifold, install a NEW gasket. An improperly installed gasket or leaking exhaust system may effect On-Board Diagnostics (OBD) II system performance.
       • Remove the oxygen sensor prior to cleaning the manifold. Do not submerge the oxygen sensor in cleaning solvent.

  1. Remove the oxygen sensor from the manifold.
  2. Clean the exhaust manifold in solvent.

    3. Caution: Wear safety glasses in order to avoid eye damage.

  3. Dry the exhaust manifold with compressed air.
  4. Inspect the heat shield for damage.

    5. Object Number: 1594345 Size: SH
  5. Use a straight edge and a feeler gage and measure the exhaust manifold mounting face for warpage.

    6. An exhaust manifold face with warpage in excess of 0.25 mm (0.0100 in) may cause an exhaust leak and may effect OBD II system performance. Exhaust manifolds not within specifications must be replaced.