Push the piston ring to the middle of the cylinder using the piston.
Fig. 2.155. Checking the gaps in the piston ring lock: 1 – piston ring; 2 – piston; 3 – feeler gauge
Measure the ring gap in the lock with a set of feeler gauges (fig. 2.155).
Gaps in ring locks:
- for the upper compression ring, the gap should be within 0.15–0.30 mm for K4M 760 and 761 engines, for other engines - within 0.15–0.35 mm;
- the clearance for the lower compression ring should be within 0.4–0.6 mm;
- the clearance for the oil scraper ring should be within 0.2–0.9 mm.
Replace the piston rings if the clearances are out of tolerance, and if the clearances remain out of tolerance with new rings, replace the cylinder block.