Tools Required

J 8087 Cylinder Bore Checking Gauge

1. Clean the following areas:

Notice: 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: Wear safety glasses in order to avoid eye damage.

•	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 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 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

1. Adjust the micrometer to 99.0 mm (3.897 in).



2. Insert the bore gauge into the micrometer and zero the bore gauge dial.
3. Use a bore gauge and measure the cylinder bore for taper, out-of-round, and oversize.

Slide the bore gauge up and down throughout the length of the cylinder bore. Check the bore both parallel and perpendicular to the centerline of the crankshaft.

A cylinder bore that measures 99.0-99.018 mm (3.897-3.898 in) may be honed and serviced with a standard size piston.

A cylinder bore that exceeds the maximum diameter must be serviced with an oversized piston.