Engine Block Cleaning and Inspection: Notes

Tools Required 

• J 8087  Cylinder Bore Gage
• J 42385-100  Head/Main Bolt Thread Repair Kit
Fig 1: View Of Cylinder Bore Gage
Courtesy of GENERAL MOTORS CORP.

1. Clean the following areas:
   NOTE: Do not use a caustic solution to clean the aluminum engine block.

   Important:  When cleaning an engine block in a thermal type oven, do not exceed 232°C (450°F).

   • The engine block in the solvent Remove all sludge, dirt, or debris. Refer to CLEANLINESS AND CARE  .
   CAUTION: Refer to SAFETY GLASSES CAUTION .
   • Dry the block with compressed air.
   • The gasket surfaces

     Refer to REPLACING ENGINE GASKETS  .

   • The coolant passages
   • The oil galleries
   • The main bearing caps
   • The engine block head bolt holes for threadlocking material

     Thread repair 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 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