A) Using a scraper, clean the bottom of the piston from carbon deposits.
b) Clean the ring grooves using the broken ring.
V) Using solvent and a soft brush, clean the piston.
Note: Do not use a metal brush.
2. Check piston diameter and clearance between piston and cylinder.
Attention: all measurements must be carried out at a temperature of 20°C.
A) Using a micrometer, measure the piston diameter at a distance of 28 mm or 24 mm from the top surface of the piston crown in a plane perpendicular to the axis of the piston pin and passing through its center.
Piston diameter:
- Rated - 85.915-85.945 mm
- Repair size increased by 0.50 mm (O/S) - 86.415-86.445 mm
- Repair size increased by 0.75 mm (O/S) - 86.665-86.695 mm
- Repair size increased by 1.00 mm (O/S) - 86.915-86.945 mm
b) Measure the cylinder diameter in the transverse direction, subtract the piston diameter from the cylinder diameter and calculate the clearance.
- Gap - 0.075 - 0.095 mm
If the clearance is too large, replace the piston or bore all four cylinders and replace all four pistons.
3. Check the clearance between the ring and the piston groove with a feeler gauge.
- Gap - 0.03-0.07 mm
If the clearance is out of tolerance, replace the piston.
4. Check up a backlash in the lock of a piston ring.
A) Install the ring in the cylinder.
b) Using the piston, push the ring to a depth of 94 mm, 102 mm or 110 mm from the cylinder block split plane.
V) Using a feeler gauge, measure the lock clearance.
Nominal clearance in the lock:
- rings No. 1 - 0.22-0.51 mm
- rings No. 2 - 0.15-0.47 mm
- oil scraper ring - 0.13-0.50 mm
Maximum clearance in the lock:
- rings No. 1 - 1.11 mm
- rings No. 2 - 1.07 mm
- oil scraper ring - 1.10 mm
If the clearance is greater than the maximum, replace the piston ring. If the clearance is greater than maximum even with a new ring, bore all four cylinders and use oversized piston rings.
5. Check the connecting rods.
Using a connecting rod tester, check the connecting rods for bending and twisting.
Maximum flex is 0.05mm per 100mm crank length.
If the amount of bend is greater than this value, replace the connecting rod.
Maximum twist is 0.15mm per 100mm crank length.
If the amount of twist is greater than this value, replace the connecting rod.
Attention: when replacing the connecting rod, install the same number of liners that is stamped on the cap of the new connecting rod.