Disassembly and Assembly

Cylinder Head - 2.5L (QR25DE):

CAUTION: When installing camshafts, chain tensioners, oil seals or other sliding parts, lubricate contacting surfaces with new engine oil.
Apply new engine oil to threads and seat surfaces when installing the cylinder head, camshaft sprocket, crankshaft pulley and camshaft bracket.
Attach tags to valve lifters so all parts are assembled in their original position.

DISASSEMBLY
1. Remove the valve lifter.
Note installation point.







2. Remove the valve collet.
Compress valve spring with valve spring compressor. Remove valve collet with magnet driver.

3. Remove valve spring retainer and valve spring.

CAUTION: Do not remove valve spring seat from valve spring.

4. Push valve stem to combustion chamber side, and remove valve.
- Inspect valve guide clearance before removal.
- Note installation point.







5. Remove valve oil seal with valve oil seal puller.
6. When valve seat must be replaced, refer to "VALVE SEAT REPLACEMENT".
Inspection

7. When valve guide must be replaced, refer to "VALVE GUIDE REPLACEMENT".
Inspection

8. Remove spark plug with spark plug wrench.
9. Remove spark plug tube, if necessary using pliers.

CAUTION: Be careful not to damage cylinder head. Do not remove spark plug tube if not necessary. Once removed, the spark plug tube cannot be reused because of deformation.









ASSEMBLY
1. Install valve guide.
2. Install valves.
3. Install valve oil seal. Install with valve oil seal drift to match dimension in illustration.
4. Install valve.
Install larger diameter to intake side.







5. Install valve spring. Install smaller pitch (valve spring seat side) to cylinder head side.
Note the identification color of the valve spring: Intake: blue

Exhaust: yellow

6. Install valve spring retainer.
7. Install valve collet.
Compress valve spring with valve spring compressor. Install valve collet with magnet wand. Tap stem edge lightly with plastic hammer after installation to check its installed condition.

8. Install valve lifter.







9. Install spark plug tube.
a. Remove old liquid gasket from cylinder head side mounting hole.
b. Apply liquid gasket all around on spark plug tube with a 12 mm (0.47 inch) width from edge of spark plug tube on the press fit side.
Use Genuine Anaerobic Liquid Gasket or equivalent.

c. Press fit spark plug tube so that height is to "H" is shown.

Press fit height "H" standard value i:..................38.55 - 38.65 mm (1.518 - 1.522 inch)

CAUTION: When press fitting be careful not to deform spark plug tube.
After press fitting, wipe off any protruding liquid gasket on top surface of cylinder head.

10. Install spark plug.