LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2010 >> Cobalt LS, 4D Sedan, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (Cylinder Head) >> Camshaft Inspection

Camshaft Inspection

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Do not rotate the camshaft during inspection.
  1. Remove the rocker arm assembly (see ROCKER ARM ASSEMBLY REMOVAL  ).
  2. Put the camshaft and camshaft holders on the cylinder head, then tighten the bolts to the specified torque.

    Specified Torque 

    8 mm Bolts: 

    22 N.m (2.2 kgf.m, 16 lbf.ft) 

    Apply new engine oil to the bolt threads and flange. 

    8 mm Bolts: (11), (13) 

    20 N.m (2.0 kgf.m, 14 lbf.ft) 

    Apply new engine oil to the bolt threads and flange. 

    6 mm Bolt: (12) 

    12 N.m (1.2 kgf.m, 8.7 lbf.ft) 

    Apply new engine oil to the bolt threads and flange. 

    Fig 1: Identifying Camshaft Holders Bolts Tightening Sequence
    G06428928
  3. Seat the camshaft by pushing it toward the rear of the cylinder head.
  4. Zero the dial indicator against the end of the camshaft, then push the camshaft back and forth, and read the end play. If the end play is beyond the service limit, replace the cylinder head and recheck. if it is still beyond the service limit, replace the camshaft.

    Camshaft End Play 

    Standard (New): 0.05-0.15 mm (0.002-0.006 in) 

    Service Limit: 0.3 mm (0.01 in) 

    Fig 2: Checking Camshaft End Play
    G06428929
  5. Loosen the camshaft holder bolts two turns at a time, in a crisscross pattern. Then remove the camshaft holders from the cylinder head.
  6. Lift the camshaft out of the cylinder head, wipe it clean, then inspect the lift ramps. Replace the camshaft if any lobes are pitted, scored, or excessively worn.
  7. Clean the camshaft journal surfaces in the cylinder head, then set the camshaft back in place. Place a plastigage strip across each journal.
  8. Install the camshaft holders, then tighten the bolts to the specified torque as shown in step 2.
  9. Remove the camshaft holders. Measure the widest part of plastigage on each journal.
    • If the camshaft-to-holder clearance is within limits, go to step  11.
    • If the camshaft-to-holder clearance is beyond the service limit and the camshaft has been replaced, replace the cylinder head.
    • If the camshaft-to-holder clearance is beyond the service limit and the camshaft has not been replaced, go to step 10.

    Camshaft-to-Holder Oil Clearance 

    Standard (New): 0.050-0.089 mm (0.0020-0.0035 in) 

    Service Limit: 0.10 mm (0.004 in) 

    Fig 3: Measuring Widest Part Of Plastigage On Each Journal
    G06428930
  10. Check the total runout with the camshaft supported on V-blocks.
    • If the total runout of the camshaft is within the service limit, replace the cylinder head.
    • If the total runout is beyond the service limit, replace the camshaft and recheck the camshaft-to-holder oil clearance. If the oil clearance is still out of tolerance, replace the cylinder head.

    Camshaft Total Runout 

    Standard (New): 0.03 mm (0.001 in) max. 

    Service Limit: 0.04 mm (0.002 in) 

    Fig 4: Checking Total Runout With Camshaft Supported On V-Blocks
    G06428931
  11. Measure the cam lobe height.

    Cam Lobe Height Standard (New): 

    CAM LOBE HEIGHT SPECIFICATION

      INTAKE EXHAUST
    SEC 35.854 mm (1.4116 in) 35.470 mm (1.3965 in)
    PRI 29.700 mm (1.1693 in) 29.900 mm (1.1772 in)

    PRI: Primary

    SEC: Secondary

    Fig 5: Measuring Cam Lobe Height
    G06428932