Chevrolet Silverado / GMC Sierra. Manual - part 139
Fig. 466: Cleaning Piston Ring Grooves
Courtesy of GENERAL MOTORS CORP.
3. Clean the piston ring grooves with a suitable ring groove cleaning tool.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado
Fig. 467: Identifying Piston Damage Inspection Areas
Courtesy of GENERAL MOTORS CORP.
4. Clean the piston oil lubrication holes and slots.
5. Inspect the piston for the following:
Eroded areas (1) on the top of the piston
Scuffed or damaged skirt (2)
Damage to the pin bore (3)
Cracks in the piston ring lands, the piston skirt, or the pin bosses
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado
Piston ring grooves for nicks, burrs, or other warpage which may cause the piston ring
to bind
6. Inspect the piston pin for scoring, wear or other damage.
Fig. 468: Inserting Piston Ring Into Ring Groove
Courtesy of GENERAL MOTORS CORP.
7. Measure the piston ring-to-piston ring groove side clearance.
1. Insert the edge of the piston ring into the piston ring groove.
2. Roll the piston ring completely around the piston.
If binding is caused by a distorted piston ring groove, MINOR imperfections may
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado
be removed with a fine file.
If binding is caused by a distorted piston ring, replace the piston ring.
Fig. 469: Measuring Piston Ring Side Clearance
Courtesy of GENERAL MOTORS CORP.
8. Measure the piston ring side clearance with a feeler gauge.
9. If the side clearance is too small, try another piston ring set.
10. If the proper piston ring-to-piston ring groove clearance cannot be achieved, replace the
piston and pin assembly.
11. To determine the proper piston ring side clearance, refer to Engine Mechanical
Specifications.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado