Block and Piston Inspection: Inspection
How to use this service information .
- Engine Block Warpage - Inspect
Preconditions
Figure 1
Figure 2
Procedure/Specifications
- Check the top of the block for warpage. Measure along the edges and across the center as shown. (Figure 1 and 2)
Tool Details (Figure 1)
Name a Precision Straight Edge (Commercially Available) b Feeler Gauge Specifications
Standard Value (New) 0.07 mm (0.0028 in) max. Result
- If the measurement is not within specifications, replace the engine block .
- Cylinder Bore - Inspect
Preconditions
Figure 1
Figure 2
Procedure/Specifications
1. Measure the wear and taper in direction Y and X at three levels inside each cylinder as shown. (Figure 1 and 2)
Measurement Position (Figure 1)
Standard Value a First Measurement 10 mm (0.39 in) b Second Measurement 50 mm (1.97 in) c Third Measurement 110 mm (4.33 in) Cylinder Bore Code Location (Figure 2)
Position Cylinder Bore No. d No. 1 e No. 4 Specifications (Cylinder Bore Size)
Cylinder Bore Code Standard Value (New) Service Limit A or I 86.010-86.020 mm (3.38621-3.38661 in) 86.070 mm (3.38858 in) B or II 86.000-86.010 mm (3.38582-3.38621 in) 86.070 mm (3.38858 in) Oversize Bore
Standard Value 0.25 86.250-86.260 mm (3.39566-3.39606 in) Specifications (Bore Taper)
Service Limit (Difference between first and third measurement) 0.050 mm (0.00197 in) 2. Hone any cored or scratched cylinder bores - Refer to: Cylinder Bore Honing or Block and Piston Inspection if needed. If the engine block is being rebored, check the piston-to- cylinder bore clearance.
Reboring Limit
Standard Value 0.25 mm (0.0098 in) max. Result
- If measurements in any cylinder are beyond the oversize bore service limit, replace the engine block .
- Piston Skirt Diameter - Inspect
Preconditions
Figure 1
Figure 2
Procedure/Specifications
1. Check the pistons for distortion or cracks.
Specifications
Object Specification Piston No distortion or cracks 2. Measure the piston skirt diameter at a point (a) from the bottom of the skirt. (Figure 1)
Measurement Position (Figure 1)
Standard Value a 11.4 mm (0.449 in) Specifications (Figure 1)
Letter Service Limit A b 85.930 mm (3.38306 in) B 85.920 mm (3.38267 in) Tool Details (Figure 2)
Name c Micrometer Result
- If the measurement is not within specifications, replace the piston.
- Piston-to-Cylinder Bore Clearance - Inspect
Preconditions
Procedure/Specifications
- Calculate the difference between the cylinder bore diameter and the piston diameter.
Specifications
Service Limit a 0.05 mm (0.0020 in) Result
- If the measurement is not within specifications, the clearance is near, or exceeds the service limit, inspect the piston and the cylinder bore for excessive wear.