Cylinder head and valves.
1 - hydraulic compensator (engine 2.7 l), 2 - crackers, 3 - valve spring plate, 4 - valve stem seal, 5 - valve spring, 6 - valve spring seat, 7 - exhaust valve guide, 8 - intake valve guide, 9 - cylinder head bolt, 10 - washer (engines 2.0 l / 2.4 l), 11 - cylinder head (engines 2.0 l / 2.4 l), 12 - right cylinder head (engine 2.7 l), 13 - left cylinder head (engine 2.7 l), 14 - intake valve seat, 15 - exhaust valve seat, 16 - intake valve, 17 - exhaust valve, 18 - cylinder head gasket, 19 - cylinder block.
Disassembly
1. With a special tool (valve spring compressor and adapter) remove the crackers from the valve spring plate. Then remove the valve spring cap, valve spring, valve spring seat and valve.
Note: Store the parts for each valve separately as a set to avoid confusion during installation.
Engines 2.0 l / 2.4 l.
2. With a special tool (puller) remove the oil caps.
Note: Valve stem seals must not be reused.
Engines 2.0 l / 2.4 l.
Examination
Cylinder head
1. Check the cylinder head for cracks, damage and signs of coolant leakage. If cracks are found, replace the cylinder head.
2. Completely clean the cylinder head from scale, carbon deposits and residues of old sealant and gasket. After cleaning the oil passages, blow them out with compressed air to check that they are not clogged.
Engines 2.0 l / 2.4 l.
3. Check the flatness of the mating surface of the cylinder head in the directions shown in the figure. If the flatness exceeds the limit in either direction, either replace the cylinder head or lightly sand the mating surface of the cylinder head.
Non-flatness of the mating surface of the cylinder head:
- Rated value: less than 0.03mm
- Maximum allowable value:
- 2.0L/2.4L engines: 0.2mm
- 2.7L engine: 0.05mm
Non-flatness of the cylinder head mounting surface for manifolds:
- Rated value: no more than 0.15 mm
- Limit value: no more than 0.30 mm
Engines 2.0 l / 2.4 l. | 2.7L engine |
Valves
1. Use a wire brush to thoroughly clean the valve.
2. Check each valve for wear, damage, and deformation of the poppet and area "IN" valve stem. Replace valve if necessary. If at the end "A" If the valve stem is dented or there is significant wear, refinish the end of the valve stem if necessary. The thickness of the layer to be removed during mechanical processing of the end of the valve stem should be minimal. In addition, process the working chamfer of the valve seat.
Valve length:
- Rated value:
- Engines 2.0 p / 2.4 l:
- Intake: 109.5mm
- Exhaust: 109.7mm
- Engine 2.7L:
- Intake: 96.10mm
- Exhaust: 97.15mm
Angle of inclination of the working chamfer:
- Rated value: 45°-45.5°
3. Replace the valve if the valve disc thickness is less than the limit.
Valve plate thickness:
- Rated value:
- 2.0L/2.4L engines:
- Inlet valve: 1.00mm
- Exhaust valve: 1.50mm
- Engine 2.7L:
- Inlet valve 1.00mm
- Exhaust valve 1.30mm
- Maximum allowable value:
- 2.0L/2.4L engines:
- Inlet valve: 0.7mm
- Exhaust valve: 1.0mm
- Engine 2.7L:
- Inlet valve: 0.50mm
- Exhaust valve: 0.80mm
Valve seat check
Check the valve seat for signs of overheating and uneven contact with the valve face. If necessary, or restore (machine) or replace the valve seat. Check the valve guide for wear before rebuilding the valve seat. If the guide bushing is worn, replace it first and then rebuild the valve seat.
Valve springs
1. Check the free length of each valve spring. If the length of the spring is less than the limit, replace the valve spring.
- Engines 2.0 l / 2.4 l:
- Rated value:
- Spring free length: 45.82 mm
- Spring length under load 253 N: 40.00 mm
- Maximum allowable value:
- Spring free length: 44.82 mm
- Engine 2.7L:
- Rated value:
- Spring free length: 42.5 mm
- Spring length under load 219 N: 35.0 mm
- Maximum allowable value:
- Spring free length: 41.5 mm
- Spring length under load 219 N: 34.0 mm
2. Using a square, check the deviation of the axis of each spring from perpendicular to the supporting surface (non-perpendicularity). If the misalignment is greater than the limit, replace the valve spring.
Spring axis deflection (non-perpendicularity):
- Engines 2.0 l / 2.4 l:
- Rated value: 1.5°or less
- Limit value: no more than 4°
- Engine 2.7L:
- Rated value: 1.3°or less
- Limit value: no more than 3°
Valve guides
Check clearance between valve guide and valve stem (at several points along the length). If the clearance is greater than the limit, replace the valve guide with the next oversize.
Clearance between valve guide and valve stem:
- 2.0L/2.4L engines:
- Rated value:
- Inlet valve: 0.020-0.047mm
- Exhaust valve: 0.050-0.085mm
- Maximum allowable value:
- Inlet valve: 0.10mm
- Exhaust valve: 0.15mm
- Engine 2.7L:
- Rated value:
- Inlet valve: 0.02-0.05mm
- Exhaust valve: 0.035-0.065mm
- Maximum allowable value:
- Inlet valve: 0.10mm
- Exhaust valve: 0.15mm
Valve stem diameter:
- Rated value:
- Engine 2.7L:
- Intake: 5.965-5.980mm
- Exhaust: 5.950-5.965mm
- 2.0L/2.4L engines:
- Intake: 6.565-6.580 mm
- Exhaust: 6.530-6.550 mm
Checking hydraulic lifters
1. (Engines 2.0 l / 2.4 l) The procedure for checking hydraulic lifters is given in chapter "2.0L/2.4L Engines - Mechanical".
2. (2.7L engine) The procedure for checking hydraulic lifters is given in chapter "Engine 2.7 l - mechanical part".
Repair
Valve seat rebuild
Check the valve guide for wear before rebuilding the valve seat. If the guide bushing is worn, replace it first and then rebuild the valve seat.
Restoration of the valve seat is carried out with a special tool (cutters or on machine tools). The width of the contact surface of the valve seat must correspond to the nominal values and the contact patch must be located evenly in the center of the working chamfer of the valve disc. After restoring the valve seat, the valve and valve seat must be lapped using lapping paste.
- Valve seat angle (2.0 l/ 2.4 l): 44°-44,5°
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |
Valve seat replacement
Note: Valve seat replacement must be done on machine tools.
1. Machine (cut off) replaceable valve seat from the inside to reduce the thickness of its walls.
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |
2. Bore a hole in the cylinder head to install a valve seat of the appropriate repair size (increased diameter).
Engine 2.7 l.
3. Heat the cylinder head to approximately 250°C and press a new oversize seat into the bore of the cylinder head.
4. Lappe the valve to the new seat using lapping paste.
Valve seat contact width:
- 2.0L/2.4L engines:
- For intake: 0.9-1.3mm
- For graduation: 0.9-1.3mm
- 2.7L engines:
- For intake: 1.1-1.5mm
- For Graduation: 1.3-1.7mm
Valve guide replacement
1. With a special tool (mandrel for installing the guide bush) Press the old valve guide out of the cylinder head towards the gasket surface.
2. Bore the cylinder head bore to install the correct oversize valve guide (increased diameter).
3. With a special tool (mandrel for installing the guide bush) press in the new valve guide. The guide sleeve must be pressed in from the top surface of the cylinder head. Pay attention to the difference in the length of the guide bushings for the intake and exhaust valves.
Valve guide length:
- Engines 2.0 l / 2.4 l:
- For intake valve: 45.5mm
- For exhaust valve: 50.5mm
- Engine 2.7L:
- For intake valve: 39.0 mm
- For exhaust valve: 43.0 mm
Note: Do not install the valve guide if it does not match the oversize.
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |
4. After installing the valve guide, insert the new valve and check that the gap between the valve guide and the valve stem is correct.
5. After replacing the valve guide, check that the valve is seated correctly. Rework the valve seat if necessary.
Table of repair dimensions of holes for valve seats.
Table. Repair dimensions of valve guides (engines 2.0 l / 2.4 l).
Repair size, mm | Label | Bore diameter of the cylinder head for the valve guide, mm |
0,05 | 5 | 12,050-12,068 |
0,25 | 25 | 12,250-12,268 |
0,50 | 50 | 12,500-12,518 |
Table. Repair dimensions of valve guides (engine 2.7 l).
Repair size, mm | Label | Bore diameter of the cylinder head for the valve guide, mm |
0,05 | 5 | 11,050-11,068 |
0,25 | 25 | 11,250-11,268 |
0,50 | 50 | 11,500-11,518 |
Assembly
Note:
- Thoroughly clean all parts before assembly.
- Apply engine oil to all rubbing and rotating parts.
1. Install the valve spring seat.
2. Install the oil scraper cap.
With a special tool (mandrel for installing the oil scraper cap) Install the valve stem seal with a light blow.
Note:
- Reuse of valve stem seals is not allowed.
- Improper installation of the valve stem seal can result in oil leaks through the valve guide.
3. Lubricate the valve stem with engine oil. Insert the valve into the valve guide. Do not apply force when passing the valve stem through the valve stem seal. After installing the valve, check the smoothness of its movement.
4. Install the valve spring so that the painted coil of the spring is located near the spring plate (up), and then install the valve spring cap.
5. With special tool (valve spring compressor and adapter) compress the valve spring and install the crackers. Before removing the special tool after installing the valve, check that the nuts are securely installed.
Note: when compressing the valve spring, make sure that the spring plate does not touch the valve stem seal.
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |