Removal and Installation

Cylinder Head - 2.5L (QR25DE):

REMOVAL
1. "Perform The Fuel Pressure Release Procedure" .
2. Remove the strut tower brace.
3. Drain engine coolant and engine oil.
4. Remove the engine undercovers.
5. Remove the timing chain.
6. Remove the camshafts.
7. Remove the exhaust manifold.
8. Support the engine with suitable hoist and floor lack.







9. Remove cylinder head loosening bolts in the numerical order as shown.
10. If necessary to transfer to new cylinder head or remove for reconditioning, remove the intake manifold collector, intake manifold, and fuel tube assembly.


INSPECTION AFTER REMOVAL
Outer Diameter of Cylinder Head Bolts







Cylinder head bolts are tightened by using the plastic zone (Torque-to-yeild) tightening method. Whenever the size difference between d1 and d2 exceeds the limit, replace the bolts with new ones.

- Subtract the head bolt diameter measurement taken at d2 from the head bolt diameter measurement taken at d1. If the difference between d1 and d2 exceeds the limit, replace the bolts with new ones.

Limit (d1 - d2): 0.23 mm (0.0091 inch) or less

If reduction of outer diameter appears in a position other than d2, use it as d2 point.


INSTALLATION
1. Install a new cylinder head gasket.





2. Follow the steps below to tighten the cylinder head bolts in the numerical order as shown.





CAUTION:
- If cylinder head bolts are re-used, check their outer diameters before installation.

- Apply new engine oil to the threads and the seating surfaces of mounting bolts.

Cylinder head bolts
Step 1: 98.1 Nm (10 kg-m, 72 ft. lbs.)
Step 2: 0 Nm (0 kg-m, 0 ft. lbs.) (loosen)
Step 3: 34.3 - 44.1 Nm (3.5 - 4.4 kg-m, 26 -32 ft. lbs.)
Step 4: 75° - 80° (target: 75°) clockwise
Phase 5: 75° - 80° (target: 75°) clockwise





CAUTION: Check and confirm the tightening angle by using an angle wrench or protractor. Avoid judgment by visual inspection without the tool.

3. Installation of the remaining components is in reverse order of removal.