Piston and connecting rod.
1 - connecting rod cap, 2 - lower connecting rod bearing, 3 - bolt (engines 2.0 l / 2.4 l), 4 - compression ring No. 1, 5 - compression ring No. 2, 6 - oil scraper ring, 7 - piston, 8 - piston pin, 9 - connecting rod, 10 - upper connecting rod bearing, 11 - piston and connecting rod assembly (engine 2.7 l).
Note: (engines 2.0 l / 2.4 l) Tighten the connecting rod cap locknut to yield strength.
Removal and disassembly
Attention: position the removed parts (connecting rods, connecting rod caps, connecting rod bearing shells) in order of their respective cylinder numbers to ensure correct reassembly.
When removing parts, refer to the figure "Piston and connecting rod".
When removing parts, pay attention to the following operations.
- A) Loosen the connecting rod cap bolts, then remove the connecting rod cap and lower connecting rod bearing.
- b) Push the piston and connecting rod assembly out of the cylinder block towards the head gasket surface.
Attention: be careful when removing the piston with connecting rod assembly, do not hit the connecting rod on the cylinder surface and the crankshaft journal.
- V) Mark the cylinder number on the side of the connecting rod for ease of reassembly.
Engines 2.0 l / 2.4 l. | Engines 2.7 liters. |
Examination
Piston and piston pin
1. Check each piston for scratches, nicks, wear, or other defects. Replace piston if defective.
2. Check each piston ring for kinks, damage or significant wear. Replace defective rings.
If a piston needs to be replaced, its piston rings must be replaced at the same time.
3. Checking the piston pin.
- A) Try to insert the piston pin into the piston bore with thumb force. There should be resistance to this. Replace the pin if it slides easily into the hole or if there is significant play. Replace piston pin if defective.
- b) Measure the piston pin diameter.
- Rated value (engines 2.0/2.4 l): 22.00-22.01mm
Piston rings
1. Measure the clearance between the piston ring and the piston groove. If the measured clearance exceeds the limit, install a new piston ring and re-measure the clearance. If the measured gap again exceeds the limit value, replace the piston and rings as an assembly. If the measured clearance is less than the maximum allowable value, then replace only the piston rings.
Gap between piston ring and piston groove:
- Rated value:
- 2.0L/2.4L engines:
- Compression rings: 0.02-0.06mm
- Oil scraper ring: 0.06-0.15 mm
- 2.7L engines:
- Compression ring #1: 0.04-0.08mm
- Compression ring #2: 0.03-0.07mm
- Maximum allowable value:
- Compression ring #1: 0.1mm
- Compression ring #2: 0.1mm
Piston ring groove width:
- 2.0L/2.4L engines:
- Compression ring #1: 1.21-1.23mm
- Compression ring #2: 1.51-1.53mm
- Oil scraper ring: 2.81-2.83 mm
- Engine 2.7L:
- Compression ring #1: 1.23-1.25mm
- Compression ring #2: 1.22-1.24mm
- Oil scraper ring: 2.515-2.535 mm
2. For measurement of a backlash in the lock of a piston ring establish a piston ring in an opening of the cylinder.
Place the ring at right angles to the generatrix of the cylinder wall, carefully moving it down with the piston. Measure the gap in the ring lock with a flat feeler gauge. If the measured clearance exceeds the maximum allowable value, then replace the piston ring.
Piston ring gap:
- Rated value:
- 2.0L / 2.4L engines:
- Compression ring #1: 0.25-0.35 mm
- Compression ring #2: 0.40-0.55mm
- Oil scraper ring: 0.1-0.4 mm
- Engine 2.7 l:
- Compression ring #1: 0.20-0.35mm
- Compression ring #2: 0.37-0.52mm
- Oil scraper ring (scrapers:) 0.20-0.70mm
- Maximum allowable value:
- Compression rings #1 and #2: 0.8mm
- Oil scraper ring: 1.0 mm
3. (2.7L engine) When replacing piston rings without boring the cylinders to the repair size, check the clearance in the ring lock at a point located at the bottom of the cylinder (zone of least wear).
Piston ring size identification marks:
- Nominal Size: Unmarked
- Repair size 0.25 mm: 25
- Repair size 0.50 mm: 50
Note: The oversize identification mark is located on the top of the piston ring near the ring lock.
Connecting rods
1. When installing the connecting rod cap, make sure that the cylinder number marks (made during disassembly) matched on the connecting rod and the connecting rod cap. When installing a new connecting rod, make sure that the retaining grooves of the bushings in the connecting rod cap and connecting rod are on the same side.
Engines 2.0 l / 2.4 l. | Engines 2.7 liters. |
2. Replace the connecting rod if there is damage to the end surface of the upper or lower heads. If bending or twisting of the connecting rod is present, or the surface of the piston pin bore in the upper end of the connecting rod is significantly worn, replace the connecting rod.
Rated value:
- Twist: 0.1mm or less
- Bend: 0.05mm or less
Repair (piston pin replacement)
1. Using special tools, disassemble and reassemble the piston and connecting rod assembly.
2. The piston pin is pressed into the upper head of the connecting rod, and the piston slides over it at a certain temperature.
3. The set of special tools consists of a base with a stand and inserts, guides, adapters, a push rod for removal and a push rod for installation. When removing or installing a piston pin, the piston is held on the base of the tool. Piston guides make it easier to position the piston pin when removing and installing it when the connecting rod rests on the pedestal inserts.
4. To remove the piston pin, place the piston on the base and position the connecting rod on the pedestal insert. Insert push rod (for removal) through the arc of the top of the base into the piston pin and remove the pin with a press.
5. When installing a new pin, the appropriate crank support insert must be installed.
6. Position the top end of the connecting rod inside the piston. On one side of the piston, insert the appropriate guide through the piston and connecting rod, then slightly push the guide back by hand so that it is held by the piston. On the other side of the piston, insert the piston pin and place the piston and connecting rod together on the base of the tool with the pin guide on the bottom.
Note: The guide is needed to center the connecting rod in relation to the piston bosses. If assembled correctly, the finger guide will be exactly centered on the arc hole on the top of the base and touching the stand insert. If the wrong size pin guide is used, the piston (and connecting rod) and the piston pin will not be in line with the base bore.
7. Insert push rod (for installation) through the hole in the arc of the upper part of the base until it stops against the adapter on the piston pin and, using a hydraulic press, insert the finger into the piston and the upper head of the connecting rod. Continue pressing until the pin guide falls from the bottom of the base and the push rod rests against the arc of the top of the base.
Attention: do not exceed the maximum allowable force when pressing the piston pin at the moment when the pusher rod rests against the arc of the upper part of the base.
- Maximum allowable pressing force: 12500±5000 N
Assembly and installation
1. Install the oil ring expander.
2. Install the top oil ring scraper. To install the scraper, first place one end of the scraper between the expander and the piston groove, then, while holding the end of the scraper, press the scraper with your finger to bring it into the groove, as shown in the figure.
Attention: do not use a piston ring expander when installing oil scraper scrapers.
3. Install the lower oil scraper according to the procedure in step 2.
4. Apply engine oil to the piston and piston ring grooves all around.
Note: Make sure the scraper locks and oil ring expanders are positioned as shown.
5. Using a piston ring expander, install compression ring #2.
6. Install compression ring #1.
7. Position the locks of the rings as far apart as possible. Make sure that the lock of any ring is not on the axis of the piston pin or in a direction perpendicular to this axis.
8. Using the tool, secure the piston rings to the piston before installing the piston assembly into the cylinder.
9. Install the upper bearing shells into the connecting rods in the cylinder block.
10. Install the lower bearing shells in the connecting rod caps.
11. When installing, make sure that "anterior" piston mark and "anterior" The identification mark on the connecting rod points towards the front of the engine (to the timing belt).
12. When installing the connecting rod cap, make sure that the cylinder number marks (made during disassembly) matched on the connecting rod and the connecting rod cap. When installing a new connecting rod, make sure that the retaining grooves of the bushings in the connecting rod cap and connecting rod are on the same side.
Engines 2.7 liters.
13. When assembling, the connecting rod cap bolts should be tightened as follows:
- A) Apply oil to the threads of the mounting nuts and the connecting rod nuts and bolts.
- b) Tighten nuts of bolts of fastening of covers of rods the nominal moment of an inhaling.
Torque:
- 2.0l/2.4 engines: 20 Nm + 90°
- 2.7L engine: 16-20Nm+ (90°-94°)
Attention:
- Do not reinstall used (removed during disassembly) connecting rod cap bolts.
- When installing new connecting rod cap bolts, do not tighten them more than three times.
14. Check up a backlash between the lower head of a rod and a corresponding cheek of a cranked shaft.
- Rated value: 0.10-0.25mm
- Limit value: 0.40 mm
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |