Engine Block Cleaning and Inspection

Tools Required 

J 42385-100 Thread Repair Kit

1. Clean the following areas:
   NOTE: Do not use a caustic solution to clean the aluminum engine block.
   IMPORTANT: When cleaning the engine block in a thermal type oven, do not exceed 450° F (232° C).
   • The engine block in the solvent, to remove all sludge, dirt, or debris

     Refer to Cleanliness and Care .

     CAUTION: Refer to SAFETY GLASSES CAUTION in Cautions and Notices.
   • Dry the block with compressed air.
   • The gasket surfaces

     Refer to Replacing Engine Gaskets .

     Fig 1: Measuring J 8087

     Courtesy of GENERAL MOTORS CORP.
   • The coolant passages
   • The oil galleries
   • The main bearing caps
   • The engine block cylinder head bolt holes for threadlocking material

     Thread repair driver tool J 42385-107 may be used to clean the threads of old threadlocking material.

2. Inspect the following areas:
   • The cylinder walls for excessive scratches, gouging, or ring ridge
   • The cylinder bores for excessive ring ridge at the top of the cylinder
   • The coolant jacket for cracks
   • The valve lifter bores for excessive scoring or wear
   • The crankshaft bearing webs for cracks
   • The gasket sealing surfaces for excessive scratches or gouging

     Refer to Replacing Engine Gaskets .

   • The oil galleries for restrictions
   • All threaded bolt holes for damage
3. Measure the following areas:
   • The cylinder bores for taper
   • The cylinder bores for excessive ring ridge at the top of the cylinder