A) Use a scraper to remove carbon deposits and other carbon deposits from the piston crown.
b) Clean the piston grooves from deposits with a piece of a broken ring.
V) Clean the plunger with solvent and a soft hair brush.
Note: Do not use a metal brush.
2. Check piston and piston B rings.
A. Check clearance between piston and cylinder.
Note: there are three size groups of nominal piston diameter, indicated by marks (figures) "1", "2" And "3" respectively. The mark is applied on the piston crown with an edge in the direction perpendicular to the axis of the piston pin or on the piston crown in the center. Pay attention to the label (excavation) "before", along which the piston should be installed in the cylinder.
3S - FE, 4S - FE
4A - FE, 5A - FE, 7A - FE
2C
A) Using a micrometer, measure the piston skirt diameter at a distance of 25.4 mm (3S - FE), 26.0 mm (4S - FE); 24.5mm (4A - FE, 5A - FE, 7A - FE); 64.5 mm (2C); from the surface of the piston (below the level of the piston ring grooves) and in a direction perpendicular to the axis of the piston pin, as shown in the figure.
Nominal piston diameter:
Engine 2C:
- label "1" - 85.945 - 85.955 mm
- label "2" - 85.955 - 85.965 mm
- label "3" - 85.965 - 85.975 mm
- rem. (0,50) - 86.445 - 86.475 mm
Engine 3S - FE:
- label "1" - 85.870 - 85.880 mm
- label "2" - 85.880 - 85.890 mm
- label "3" - 85.890 - 85.890 mm
- rem. (0,50) - 86.425 - 86.455 mm
Engine 4S - FE:
- label "1" - 82.437 - 82.447 mm
- label "2" - 82.447 - 82.457 mm
- label "3" - 82.457 - 82.467 mm
- rem. (0,50) - 82.937 - 82.967 mm
- rem. (0,75) - 83.187 - 83.217 mm
Engines 4A - FE, 7A - FE:
- label "1" — 80.905 - 80.915mm
- label "2" - 80.915 - 80.925 mm
- label "3" - 80.925 - 80.935 mm
- rem. (0,50) - 81.430 - 81.460 mm
Engine 5A - FE:
- label "1" - 78.605 - 78.615 mm
- label "2" - 78.615 - 78.625 mm
- label "3" - 78.625 - 78.630 mm
- rem. (0,50) - 79.130 - 79.160 mm
b) Measure the cylinder diameters in the direction of the engine axis.
V) Find the difference between the measurements of the piston diameter and the cylinder diameter.
Clearance between cylinder and piston:
2C:
- nominal - 0.045 - 0.065 mm
- maximum - 0.15 mm
3S - FE:
- nominal - 0.120 - 0.140 mm
- maximum - 0.190 mm
4S - FE:
- nominal - 0.053 - 0.073 mm
- maximum - 0.120 mm
4A - FE, 5A - FE, 7A - FE:
- nominal - 0.085 - 0.105 mm
- maximum - 0.130 mm
If clearance is greater than maximum, replace all four pistons and bore all four cylinders. Replace the cylinder block if necessary.
Note: When using a new cylinder block, use the piston with the same mark (number), which is the diameter of the cylinder. The cylinder diameter is marked on the cylinder block in the places shown in the figure.
B. Check end clearance "compression ring - piston groove", by measuring it with a flat feeler gauge as shown in the figure.
Rated Clearance:
Compression ring #1:
- 3S - FE - 0.040 - 0.080 mm
- 4S - FE - 0.030 - 0.070 mm
4A - FE, 5A - FE, 7A - FE:
- T - 0.050 - 0.085 mm
- 2R - 0.045 - 0.080 mm
- 2C - 0.100 - 0.140 mm
Compression ring #2:
- 3S - FE, 4S - FE, 4A - FE, 5A - FE, 7A - FE - 0.030 - 0.070 mm
- 2C - 0.050 - 0.090 mm
Oil ring:
2C - 0.030 - 0.070 mm
4A - FE, 5A - FE, 7A - FE:
- T - 0.02 - 0.16 mm
- 2R - 0.03 - 0.11 mm
If the clearance is more than acceptable, replace the piston.
B. Check the clearance in the piston ring lock.
A) Insert the piston ring into the cylinder.
b) Use the piston to push the ring a distance of 110 mm (3S - FE, 5A - FE); 107 mm (7A - FE); 100 mm (4A - FE, 5A - FE); 120 mm (2C) from the surface of the cylinder block, as shown in the figure.
V) Use a flat feeler gauge to measure the gap in the lock.
Engine 2C:
Rated Clearance:
- compression ring No. 1 - 0.27 - 0.037 mm
- compression ring No. 2 - 0.34 - 0.47 mm
- oil scraper ring (scrapers) — 0.20 - 0.40 mm
Max Clearance:
- compression ring No. 1 - 0.98 mm
- compression ring No. 2 - 0.92 mm
- oil scraper ring (scrapers) - 1.00 mm
Engine 3S - FE:
Rated Clearance:
- compression ring No. 1 - 0.27 - 0.40 mm
- compression ring No. 2 - 0.27 - 0.41 mm
- oil scraper ring (scrapers) — 0.20 - 0.70 mm
Max Clearance:
- compression ring No. 1 - 1.00 mm
- compression ring No. 2 - 1.01 mm
- oil scraper ring (scrapers) - 1.30 mm
Engine 4S - FE:
Rated Clearance:
- compression ring No. 1 - 0.25 - 0.38 mm
- compression ring No. 2 - 0.20 - 0.32 mm
- oil scraper ring (scrapers) — 0.15 - 0.40 mm
Max Clearance:
- compression ring N°1 - 0.98 mm
- compression ring No. 2 - 0.92mm
- oil scraper ring (scrapers) - 1.00 mm
Engine 5A - FE:
Nominal Clearance: Compression Ring #1
- T - 0.25 - 0.37 mm
- 2R - 0.25 - 0.35 mm
compression ring #2
- T - 0.37 - 0.52 mm
- 2R - 0.35 - 0.50 mm
oil scraper ring (scrapers)
- T - 0.15 - 0.40 mm
- 2R - 0.10 - 0.35 mm
Max Clearance:
- compression ring No. 1 - 0.97 mm
- compression ring No. 2 - 0.95 mm
- oil scraper ring (scrapers) - 0.70 mm
Engine 4A - FE, 7A - FE:
Rated Clearance:
- compression ring No. 1 - 0.25 - 0.35 mm
- compression ring No. 2 - 0.35 - 0.50 mm
oil scraper ring (scrapers)
- T - 0.15 - 0.40 mm
- 2R - 0.10 - 0.35 mm
Max Clearance:
- compression ring No. 1 - 1.07 mm
- compression ring No. 2 - 1.02 mm
- oil scraper ring (scrapers) - 1.62 mm
If the clearance in the lock is greater than the maximum, replace the piston ring. If the gap in the lock is greater than the maximum even with a new piston ring, bore all cylinders or replace the cylinder block.
D. Check piston pin.
When the piston is heated to 60°C, the piston pin should move in the piston without significant effort. After checking, remove the piston pin.
3. Check the concentricity of the connecting rod.
A. Using the special tool and a feeler gauge, check the bending of the connecting rod as shown in the illustration. Maximum allowable bend per 100 mm length:
- 5A - FE - 0.03 mm
- the rest - 0.05 mm
If the twist is more than acceptable, replace the connecting rod together with the connecting rod cap.
In the same way, check the twisting of the connecting rod, as shown in the figure.
Maximum twist per 100 mm length:
- E series engines - 0.05 mm
- motors series C, S - 0.15 mm
B. (2C, 3S - FE) Check piston pin oil clearance.
A) Using a inside gauge, measure the inside diameter of the connecting rod bushing.
Sleeve inner diameter:
2C
- mark A - 27.011 - 27.015 mm
- mark B - 20.015 - 20.019 mm
- mark c - 20.016 - 20.021 mm
3S - FE - 22.005 - 22.017 mm
b) Using a micrometer, measure the diameter of the piston pin.
Piston pin diameter:
- 2C - 27.000 - 27.012 mm
- 3S - FE - 21.997 - 22.009 mm
V) Subtract the measured piston pin diameter from the measured bushing inside diameter.
Rated oil clearance:
- 2C - 0.007 - 0.015 mm
- 3S - FE - 0.005 - 0.011 mm
Maximum oil clearance - 0.05 mm
If the oil clearance is greater than the maximum, replace the bushing. If necessary, replace the piston and piston pin assembly.
IN. (2C, 3S - FE) If necessary, replace the connecting rod bushing.
A). Using a drift and a press, press the bushing out of the connecting rod head.
b) (3S - FE) Align the lubrication holes of the new bushing and connecting rod, and press the bushing.
(2C) Install the bushing on the special tool, fixing it with a ball in the oil (lubricant) bushing holes.
Align the lubrication holes of the bushing and connecting rod.
Using a special tool and a press, press in the bushing.
V) Measure the piston pin oil clearance and, if necessary, grind or re-grind a new bushing to the correct clearance.
G) Check piston pin operation at normal room temperature. Coat the piston pin with engine oil and push it in as shown.
G. (3S - FE) Check connecting rod bolts.
A) Screw a nut onto each bolt and make sure that the nut can be easily turned on by hand, for the full length of the bolt threads.
b) If the nut cannot be screwed on by hand, measure the outside diameter of the bolt thread with a caliper in the area where the threads are most worn.
Standard diameter:
- 3S - FE - 7.86 - 8.00 mm
Minimum Diameter:
- 3S - FE - 7.60 mm
Note: If this area is difficult to detect visually, then measure at a distance of 15 mm from the end of the bolt, as shown in the figure.
If the outer diameter of the thread is less than the minimum, replace the connecting rod bolt and nut as a single assembly.