Removal piston rings
Removal the piston pin retaining ring
Removal the piston pin
Oil hole in the connecting rod head
On 4-cylinder gasoline engines and 6-cylinder SOHC engines, the small oil hole in the connecting rod end should be located on the drive chain side.
Grooves for liners and protrusion under the piston bottom
On 6-cylinder DOHC petrol engines, the bearing grooves (1) should be located on the intake manifold side and the protrusion (2) under the piston crown should be on the flywheel side.
1. Before checking the pistons with connecting rods, remove the piston rings from the pistons and thoroughly clean the pistons.
2. To remove piston rings from pistons, spread the ring and insert two or three old feeler gauge blades evenly around the circumference of the ring and slide the ring off the piston. Be careful not to scratch the piston with the ends of the ring. Rings are very fragile and can crack if spread too much. The working edges of piston rings are very sharp, so handle them very carefully to avoid cutting yourself. Keep each set of rings with the pistons for reinstallation.
3. Clean all traces of carbon from the top of the piston.
4. Remove carbon deposits from the piston ring grooves using an old piston ring.
5. After removing the deposits, clean the piston and connecting rod with a suitable solvent and wipe dry.
6. Carefully inspect each piston for cracks around the skirt and piston pin holes.
7. Check for wear on the piston skirt, bore in the piston head, and burn marks on the top of the piston.
8. Traces of pitting corrosion on the piston indicate that coolant has entered the combustion chamber. It is necessary to find the cause of the liquid entering the combustion chamber and eliminate it.
9. Measure the piston diameter.
10. Determine the piston clearance in the cylinder by subtracting the piston diameter from the cylinder diameter and dividing by two.
11. Check each connecting rod for wear, cracks, and distortion.
12. The piston pins are installed with a sliding fit and are fixed in the piston by two retaining rings. On these engines, the pistons and connecting rods can be separated as follows.
13. Using a thin screwdriver blade, remove the retaining ring from the piston and push out the piston pin by hand. When reinstalling the piston pin, use only new retaining rings.
14. Check the piston pin and big end bearing for wear.
15. Connecting rods usually do not require replacement unless the engine has seized up beforehand.
16. Assemble the pistons with the connecting rods as follows: (see fig. Oil hole in connecting rod head, Grooves for bearing shells and protrusion under piston bottom).
17. On 4-cylinder gasoline engines and 6-cylinder SOHC gasoline engines, the small oil hole on the top of the connecting rod and the arrows on the piston crown should point toward the timing chain.
18. On 6-cylinder DOHC gasoline engines, the connecting rod bearing grooves in the connecting rod and cover should be on the intake manifold side, and the arrow on the piston crown should point toward the drive chain. The protrusion under the piston crown should point toward the flywheel.
19. On diesel engines, the bearing shell grooves in the connecting rod and connecting rod cap should be on the high-pressure fuel pump side, and the arrow on the piston crown should point toward the drive chain.
20. Lubricate the piston pin and insert it into the piston and connecting rod upper head. Check that the piston rotates easily and freely on the piston pin, then secure the piston pin with new circlips.