GMC Powertrain 4.3 L, Service Manual, Page: 76 / 196

6-66 Marine/Industrial 4.3L Engine
2000 Marine/Industrial
334378
Engine Block Clean and Inspect
Tools Required
J 8087 Cylinder Bore Gauge
Caution: Refer to Safety Glasses Caution in Cautions and
Notices.
1. Clean all the remaining sealing or gasket material from the
sealing surfaces.
2. Clean the engine block with cleaning solvent.
3. Flush the engine block with clean water or steam.
4. Clean the cylinder bores.
5. Clean the oil galleries and the oil passages.
6. Clean the scale and the deposits from the coolant
passages.
Notice: Clean all debris, dirt and coolant from the engine block
cylinder head bolt holes. Failure to remove all foreign material may
result in damaged threads, improperly tightened fasteners or
damage to the components.
7. Clean the engine block cylinder head bolt holes.
8. After cleaning the engine block, spray or wipe the cylinder
bores and the machined surfaces with clean engine oil.
9. Inspect the following areas:
• Coolant jackets (1) for cracks
•
Cylinder bores (2) for scratches or gouging
• Valve lifter bores (3) for excessive scoring or wear
•
Threaded holes (4) for damage
• Crankshaft bearing webs (5) for cracks
•
Crankshaft bearing caps (6) and the crankshaft bearing
bores (7) for damage
- The crankshaft bearing bores should be round and
uniform when measuring the inside diameter (ID).
- The surface where the crankshaft bearings contact the
crankshaft bearing bore should be smooth.
- If a crankshaft bearing cap is damaged and requires
replacement, replace the crankshaft bearing cap first,
then rebore the engine block crankshaft bearing bores
and check for proper alignment. Finally, check the
crankshaft fro the proper clearances.
• Engine block core hole plug bores (8) for damage
•
Engine block (9) fro cracks or damage
• Engine mount bosses (10) for damage