Cylinder block (engines 2.0 l / 2.4 l). 1 - oil pressure switch sensor, 2 - cylinder block, 3 - engine support bracket. | Cylinder block (engine 2.7 l). 1 - cylinder block, 2 - main bearing cap, 3 - connecting bracket for main bearing caps. |
Examination
1. Check the cylinder block for chipping, corrosion, scale deposits and rust. Also, check for cracks or other damage. Replace the block of cylinders at detection of considerable defects.
2. Using a straightedge and a flat feeler gauge, check for warpage (flatness) mating plane of the cylinder block for the gasket. Before checking, make sure that the surface of the cylinder block is free of old gasket residue and foreign particles. If the flatness exceeds the limit value, then grind the surface to an acceptable value or replace the cylinder block.
Note: The total thickness of the metal removed from the cylinder head and cylinder block during machining must not exceed 0.2 mm in total.
- 2.0L/2.4L engines:
- Rated value: 0.05mm
- Limit value: no more than 0.10 mm
- Engine 2.7L:
- Rated value: 0.03mm
- Limit value: no more than 0.05 mm
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |
3. Measure the diameter of the cylinders using the caliper indicator in three zones along the height in the directions "A" And "IN". Take measurements in the places shown in the figure:
(1) - piston TDC (compression ring stop point #1); (2) - the middle of the piston stroke; (3) - BDC piston.
Nominal cylinder diameter:
- 2.0L Engine: 85.00-85.03mm
- 2.4L engine: 86.50-86.53mm
- 2.7L engine: 86.70-86.73 mm
Engines 2.0 l / 2.4 l. | Engine 2.7 l. |
4. If either out of roundness (ovality) or the taper of the cylinder is greater than the maximum permissible value, or there are scratches or signs of seizing on the cylinder mirror (badass), then the cylinders of the block should be bored to the appropriate repair size and honed. After repair of the block of cylinders establish pistons and piston rings of the corresponding repair size.
Maximum permissible out-of-roundness and taper of the cylinder (no more):
- 2.0L/2.4L engines: 0.01mm
- 2.7L engine: 0.02mm
5. Check the mirror of each cylinder for damage and cracks.
Repair
Cylinder boring
Attention: bore all four cylinders to the same repair size. Do not bore only one cylinder to oversize.
1. If there is an influx along the perimeter of the cylinder in its upper part (ridge wear), then remove it with a special tool.
2. According to the largest diameter of the cylinder of the repaired engine, obtained as a result of measurements, determine the number of the repair size of the pistons.
Piston oversize identification marks:
- 2.0L/2.4L engines:
- Repair size: 0.50 mm
- Label: 0.50
- Engine 2.7L:
- Repair size: 0.25 mm; 0.50 mm
- Label: 0.25; 0.50
Nominal piston diameter:
- 2.0L Engine: 84.97-85.00mm
- 2.4L engine: 86.47-86.50 mm
- 2.7L engine: 86.68-86.70 mm
Attention: the identification mark of the oversize number of the piston is stamped on the piston head.
3. Measure the outside diameter of the piston to be used at the location shown in the figure.
Clearance between piston and cylinder:
- 2.0/2.4L engines: 0.02-0.04mm
- 2.7L engine: 0.01-0.03mm
Note: standard measurements of the piston diameter are made at a distance of 12 mm from the cut of the skirt in a plane perpendicular to the axis of the piston pin.
4. When repairing (boring and honing) cylinders to the repair size, calculate the bore diameter of the cylinder so that as a result of the repair, the nominal clearance between the piston and the cylinder is provided. Check that all installed pistons are the same oversize.
5. Based on the measured value of the outer diameter of the piston, calculate the bore diameter of the cylinder.
Cylinder bore diameter = Piston outside diameter + (gap between piston and cylinder) − (honing allowance).
Honing allowance:
- 2.0L/2.4L engines: 0.02mm
- 2.7L engine: 0.01mm
6. Rebore all cylinders to design diameter.
Attention:
- (2.0L / 2.4L engines) To prevent temperature deformations during boring, bore the cylinders in the following sequence: No. 2, No. 4, No. 1, No. 3.
- (2.7L engine) To prevent thermal deformations during boring, bore cylinders in the order of engine operation (1-2-3-4-5-6).
7. Honed cylinders to final finish size (piston outer diameter + clearance between piston and cylinder).
Attention:
- (2.0L / 2.4L engines) To prevent temperature deformations during honing, process cylinders in the sequence: No. 2, No. 4, No. 1 and No. 3.
- (2.7L engine) To prevent thermal deformation during honing, process cylinders in the order of engine operation (1-2-3-4-5-6).
8. Check clearance between piston and cylinder (set limit for new parts).
Rated value:
- 2.0L/2.4L engines: 0.02-0.04mm
- 2.7L engine: 0.01 - 0.03 mm
Note: Check that all installed pistons are the same oversize.