Lexus RX300 (MCU15). Service manual — part 439

A05222

Front

Recessed Heat Bolt

8 mm Hexagon Wrench

A05219

7

8

5

6

3

4

1

2

7

8

5

6

3

4

1

2

12 Pointed Head Bolt

Front

P12424

EM–40

–

ENGINE MECHANICAL

CYLINDER HEAD

LEXUS RX300 (RM785E)

36.

REMOVE CYLINDER HEADS

(a)

Using an 8 mm hexagon wrench, remove the cylinder
head (recessed head) bolt on each cylinder head, then re-
peat for the other side, as shown.

(b)

Uniformly loosen and remove the 8 cylinder head (12
pointed head) bolts on each cylinder head, in several
passes, in the sequence shown, then repeat for the other
side, as shown. Remove the 16 cylinder head bolts and
plate washers.

NOTICE:
Head warpage or cracking could result from removing
bolts in an incorrect order.

(c)

Lift the cylinder head from the dowels on the cylinder
block and place the 2 cylinder heads on wooden blocks
on a bench.

HINT:
If the cylinder head is difficult to lift off, pry between the cylinder
head and cylinder block with a screwdriver.
NOTICE:
Be careful not to damage the contact surfaces of the cylin-
der head and cylinder block.

EM0KI–02

P12683

A05224

SST

P12686

P12720

Magnetic Finger

A05276

–

ENGINE MECHANICAL

CYLINDER HEAD

EM–41

LEXUS RX300 (RM785E)

DISASSEMBLY

1.

REMOVE VALVE LIFTERS AND SHIMS

HINT:
Arrange the valve lifters and shims in the correct order.

2.

REMOVE VALVES

(a)

Using SST, compress the valve spring and remove the 2
keepers.
SST

09202–70020 (09202–00010)

(b)

Remove the spring retainer.

(c)

Remove the valve spring.

(d)

Remove the valve.

(e)

Using needle–nose pliers, remove the oil seal.

(f)

Using compressed air and a magnetic finger, remove the
spring seat by blowing air.

HINT:
Arrange the valves, valve springs, spring seats and spring re-
tainers in the correct order.

3.

REMOVE CYLINDER HEAD REAR COVER

Remove the 6 bolts, rear cover and gasket.

A05275

EM–42

–

ENGINE MECHANICAL

CYLINDER HEAD

LEXUS RX300 (RM785E)

4.

REMOVE OIL CONTROL VALVE FILTER

Remove the plug, gasket and valve filter.

EM0KJ–02

A05225

A05226

A05230

A05233

A05232

–

ENGINE MECHANICAL

CYLINDER HEAD

EM–43

LEXUS RX300 (RM785E)

INSPECTION

1.

CLEAN TOP SURFACES OF PISTONS AND CYL-
INDER BLOCK

(a)

Turn the crankshaft, and bring each piston to top dead
center (TDC). Using a gasket scraper, remove all the car-
bon from the piston top surface.

(b)

Using a gasket scraper, remove all the gasket material
from the cylinder block surface.

(c)

Using compressed air, blow carbon and oil from the bolt
holes.

CAUTION:
Protect your eyes when using high pressure compressed
air.

2.

REMOVE GASKET MATERIAL

Using a gasket scraper, remove all the gasket material from the
cylinder block contact surface.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.

3.

CLEAN COMBUSTION CHAMBERS

Using a wire brush, remove all the carbon from the combustion
chambers.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.

4.

CLEAN CYLINDER HEADS

Using a soft brush and solvent, thoroughly clean the cylinder
head.