Repair Procedure
Replace the piston and piston ring set.1. Remove the engine assembly and place on an engine stand.
Refer to the Technical Information System (TIS) applicable model and model year Repair Manual:
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Engine Assembly: Removal"
^ 2008 / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine Assembly: Removal"
2. Remove the cylinder head assembly.
Refer to TIS applicable model and model year Repair Manual:
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Cylinder Head: Removal"
^ 2008n / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Cylinder Head Gasket: Removal"
3. Remove the pistons from the connecting rods.
A. Remove the oil pan drain plug and gasket.
B. Remove the oil pan sub-assembly.
(1) Remove the 12 bolts and 2 nuts.
(2) Insert the blade of the SST between the crankcase and oil pan. Cut through the sealer and remove the oil pan.
NOTICE
Be careful NOT to damage the contact surfaces of the crankcase, chain cover, and oil pan.
C. Remove the oil pump assembly by removing the 3 bolts and gasket.
D. Remove the engine rear oil seal.
(1) Using a knife cut off the oil seal lip.
(2) Using a screwdriver (with a taped tip) pry out the oil seal.
NOTICE
After removing the oil seal, check the crankshaft for damage. If the crankshaft is damaged, smooth the surface with 400-grit sandpaper.
E. Remove the stiffening crankcase assembly.
NOTICE
Remove the stiffening crankcase as a unit. Do NOT separate the halves of the assembly, exposing the balance shaft bearings.
(1) Uniformly loosen and remove the 11 bolts in the sequence shown in the illustration.
(2) Using a screwdriver (with a taped Up) remove the crankcase by prying between the crankcase and cylinder block.
NOTICE
Be careful NOT to damage the contact surfaces of the crankcase and cylinder block.
(3) Remove the 0-ring from the cylinder block (tC ONLY).
F. Remove the piston sub-assemblies with connecting rod.
(1) Using a ridge reamer remove all the carbon from the top of the cylinder.
(2) Check that the matchmarks on the connecting rod and cap are aligned to ensure correct reassembly.
HINT
The matchmarks on the connecting rods and caps are provided for ensuring correct reassembly.
(3) Using a 12 mm socket wrench uniformly loosen the 2 bolts.
(4) Using the 2 removed connecting rod cap bolts remove the connecting rod cap and lower bearing by moving the connecting rod cap right and left.
HINT
Keep the lower bearing inserted in the connecting rod cap.
(5) Inspect the connecting rod oil clearance.
1. Clean the crank pin and bearing.
2. Check the crank pin and bearing for pitting and scratches.
3. Lay a strip of plastigage(TM) on the crank pin.
4. Check that the front mark of the connecting rod cap is facing forward.
5. Install and alternately tighten the bolts of the connecting rod cap in several steps.
Torque: 25 N*m (250 kgf*cm, 18 ft*lbf)
NOTE
The connecting cap bolts should be tightened in 2 progressive steps.
6. Mark the front of the connecting rod cap bolts with paint.
Retighten the cap bolts by 90° as shown in the illustration.
7. Remove the 2 bolts and connecting rod cap.
8. Measure the plastigage(TM) at its widest point.
tC:
Standard Oil Clearance: 0.024 to 0.048 mm (0.0009 to 0.0019 in.) Maximum Oil Clearance: 0.08 mm (0.0032 in.)
xB:
Standard Oil Clearance: 0.032 to 0.063 mm (0.0013 to 0.0025 in.) Maximum Oil Clearance: 0.063 mm (0.0025 in.)
If the oil clearance is greater than the maximum replace the connecting rod bearings. If necessary inspect the crankshaft.
NOTE
Completely remove the plastigage(TM) after the measurement.
(6) Push the piston connecting rod assembly and upper bearing through the top of the cylinder block.
HINT
^ Keep the bearing, connecting rod, and cap together.
^ Arrange the piston and connecting rod assemblies in the correct order.
(7) Repeat for the other 3 piston/connecting rod assemblies.
G. Remove the connecting rod bearings.
HINT
Arrange the removed parts in the correct order.
H. Inspect the cylinder block for warpage.
Using a precision straightedge and feeler gauge measure the warpage of the surface that is in contact with the cylinder head gasket.
Maximum Warpage: 0.05 mm (0.002 in.)
If the warpage is greater than the maximum replace the short block assembly.
I. Inspect the cylinder bore.
Visually check the cylinder bore for the presence of crosshatch and/or vertical scratches.
^ If the cylinder bore has visible crosshatch and no vertical scratches the cylinder block is OK to re-use.
^ If vertical scratches are present and can be felt with a fingernail or if the crosshatch is not visible replace the short block assembly.
J. Using a screwdriver pry out the 2 piston pin hole snap rings.
HINT
If necessary, sublet the following specialized and precision operations to a local engine machining shop.
K. Remove the piston.
(1) Gradually heat the piston to approximately 176 to 194° F (80 to 90° C).
(2) Using a plastic hammer and brass bar lightly tap out the piston pin and remove the connecting rod.
NOTE
^ The piston and pin are a matched set.
^ Arrange the pistons, pins, rings, connecting rods, and bearings in the correct order.
For additional information refer to TIS applicable model and model year Repair Manual:
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Engine Unit: Disassembly"
^ 2008 / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine Unit: Disassembly"
4. Measure and inspect the piston pin connecting rod and bearings to determine replacement part numbers and if parts are suitable for re-use.
NOTE
The following steps are required to determine the correct replacement part numbers.
HINT
If necessary, sublet the following specialized and precision operations to a local engine machining shop.
A. Inspect the original piston pin oil clearance to determine the correct replacement piston part number below.
(1) Using a caliper gauge measure the piston pin bore diameter.
Standard Piston Pin Bore Diameter:
22.001 to 22.010 mm (0.8662 to 0.8665 in.)
(2) Using a micrometer measure the piston pin diameter.
Standard Piston Pin Diameter: 21.997 to 22.006 mm (0.8660 to 0.8664 in.)
If the diameter is NOT as specified replace the piston pin.
(3) Using a caliper gauge measure the connecting rod small end bore diameter.
Standard Connecting Rod Small End
Bore Diameter:
22.005 to 22.014 mm (0.8663 to 0.8667 in.)
If the diameter is NOT as specified replace the connecting rod.
B. Inspect the connecting rod bolt.
Using vernier calipers measure the tension portion diameter of the bolt.
Standard Diameter: 7.2 to 7.3 mm (0.283 to 0.287 in.)
Minimum Diameter: 7.0 mm (0.276 in.)
If the diameter is less than the minimum replace the connecting rod bolt.
For additional information refer to TIS applicable model and model year Repair Manual:
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Engine Unit: Inspection"
^ 2008 / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine"
Unit: Inspection"
5. Install the new pistons and rings and reassemble the engine in reverse order of disassembly. For additional information refer to TIS applicable model and model year Repair Manual:
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Engine Unit: Reassembly"
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Cylinder Head: Installation"
^ 2008 / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine
Unit: Reassembly"
^ 2008 / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Cylinder Head Gasket: Installation"
6. Install the engine.
Refer to TIS applicable model and model year Repair Manual:
^ 2007 / 2008 / 2009 tC:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical:
Engine Assembly: Installation"
^ 2008 / 2009 xB:
Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine
Assembly: Installation"
7. Test drive the vehicle to verify normal operation.