Pistons and connecting rods — check (Opel Vectra B)

Piston and connecting rod

Examination

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, loosen the ring and insert two or three old feeler gauge blades evenly around the circumference under the ring and slide the ring off the piston using them.

Warning! Be careful not to scratch the piston with the ring ends. The rings are very fragile and can crack if you squeeze them too hard. The working edges of the 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. On all petrol engines the piston pins are pressed into the upper head of the connecting rod, so connecting rod replacement must be carried out in a specialized workshop.

13. On diesel engines, 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.



14. 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.



15. Check the piston pin and big end bearing for wear.

16. Connecting rods usually do not require replacement unless the engine has seized up beforehand.





17. On a 1.7L engine, assemble the piston and connecting rod so that the timing mark on the piston head (indicated by the arrow) was located on the same side as the mark on the connecting rod (indicated by the arrow).

18. On 2.0L engines, assemble the piston and connecting rod so that the arrow on the piston head points in the opposite direction from the mark on the connecting rod.





19. Lubricate the piston pin and insert it into the piston and connecting rod small end. Check that the piston rotates freely and easily on the piston pin, then secure the piston pin with new circlips. Check that each circlip is correctly positioned in the piston groove. On 2.0L engines, install the circlips with their locks facing up.

20. On 2.0L engines, the snap ring cutout should face up on the piston.