For 1990-2009 cars

Caution: Bodily injury may occur if the cleaning solvent is inhaled or exposed to the skin.

Important: Clean the piston ring grooves of carbon to the bare metal. Do not scrape the piston skirt.

1. Clean the sludge and carbon from the following components:

• | The piston

• | The piston pin

• | Soak the pin in a cleaning solvent in order to remove the varnish from the piston.

• | The connecting rod

2. Clean the piston ring grooves using a suitable ring groove cleaning tool.
3. Clean the oil lubrication holes and slots.
4. Inspect the connecting rod for bending or twisting.

4.1. | Install the connecting rod cap.

4.2. | Place the connecting rod assembly on a checking fixture. Inspect the assembly for bending or twisting.

4.3. | Do not attempt to straighten the connecting rod.

Ensure that the connecting rod meets the following conditions:

• | The connecting rods are not bent more than 0.18 mm (0.007 in).

• | The connecting rods are not twisted more than 0.038 mm (0.0015 in).

4.4. | Replace any bent or twisted connecting rods.

4.5. | Inspect the new connecting rods before using the new rods.

5. Inspect the connecting rod bearings for craters or pockets.

Flattened sections on the connecting rod bearing halves may indicate fatigue.

6. Inspect the connecting rod bearings for excessive scoring or discoloration.
7. Inspect the connecting rod bearings for dirt or debris imbedded into the connecting rod bearing halves.
8. Inspect the connecting rod bearings for improper seating indicated by bright, polished sections of the bearings.
9. Inspect the inside of the connecting rod bearing and the outside diameter of the connecting rod bearing journal for wear. This indicates high spots.
10. Inspect the connecting rod bearing bore for taper and out-of-round.
11. Inspect the connecting rod piston pin bore for taper and out-of-round.
12. Inspect the connecting rod bores for nicks or gouges.
13. Inspect the piston for the following conditions:

• | Damage to the top of the piston (1)

• | Scoring of the skirt (2)

• | Scoring of the piston pin bore (3)

• | Broken ring groove lands

14. Inspect the piston pin for scoring or galling caused by improper installation.

Important: Take the measurements of the components with the components at normal room temperature.

15. Measure the piston diameter. When measuring the piston for size or taper, ensure that the measurement is made as shown when the piston pin is removed. If the piston is worn or damaged, replace the piston using a standard or oversize piston.
16. Inspect the piston ring-to-piston ring groove side clearance. Complete the following steps:

16.1. | Insert the edge of the piston ring into the piston ring groove.

16.2. | Roll the piston ring completely around the piston.

16.3. | If binding is caused by a distorted piston ring groove, you may remove minor ring groove imperfections using a fine file.

16.4. | If binding is caused by a distorted piston ring, replace the piston ring.

17. Measure the piston ring side clearance using a feeler gauge.
18. If the side clearance is too small, try another piston ring set.
19. If a proper piston ring-to-piston ring groove clearance cannot be achieved, replace the piston.
20. Measure the piston pin diameter using an outside micrometer.
21. Measure the piston pin bore using an inside micrometer.
22. Subtract the piston pin diameter from the piston pin bore diameter in order to determine the piston pin-to-piston pin bore clearance.
23. Replace the piston and the piston pin if the piston and the piston pin are not within specifications.
24. Place the piston into the cylinder at the bottom of the ring travel.

Important: Measure the piston ring in the cylinder in which the piston may be used.

25. Place a piston ring on top of the piston.
26. Back off the piston.
27. Measure the ring gap. If the gap is below specification, increase the gap by carefully filing off excess material.