Lexus SC300 / Lexus SC400. Manual — part 367

40. DISCONNECT MAIN HEATED OXYGEN SENSOR

CONNECTORS
Disconnect the RH and LH oxygen sensor connectors.

41. REMOVE CYLINDER HEADS
(a) Uniformly loosen the ten cylinder head bolts one side of each

cylinder head in several passes, in the sequence shown,
then do the other side as shown. Remove the 20 cylinder
head bolts and plate washers.

NOTICE:

•

Cylinder head warpage or cracking could result from

removing bolts in incorrect order.

•

Do not drop the plate washer for cylinder head bolt into

portion A of the cylinder head. If dropped into portion A,

the plate washer will pass through the cylinder head and

cylinder block into the oil pan.

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EG–91

(b) 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 off, pry between the cylinder
head and cylinder block with a screwdriver.

NOTICE: Be careful not to damage the contact surfaces of the

cylinder head and cylinder block.

42. REMOVE EXHAUST MANIFOLD FROM RH CYLINDER

HEAD

(a) Remove the 3 bolts and heat insulator.

(b) Remove the main heated oxygen sensor.

(c) Remove the 8 nuts, exhaust manifold and gasket.

43. REMOVE EXHAUST MANIFOLD FROM LH CYLINDER

HEAD

(a) Remove the 3 bolts and heat insulator.

EG–92

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(b) Remove the main heated oxygen sensor.

(c) Remove the 8 nuts, exhaust manifold and gasket.

EG11C–06

CYLINDER HEAD DISASSEMBLY

(See Components for Removal and Installation)
1.

REMOVE VALVE LIFTERS AND SHIMS

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

2. REMOVE

VALVES

(a) Using SST, compress the valve spring and remove the 2

keepers.
SST 09202–70010

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EG–93

(b) Remove the following parts:

(1) Spring

retainer

(2) Valve

spring

(3) Valve
(4) Spring

seat

HINT: Arrange the valves, valve springs, spring seats and
spring retainers incorrect order.

(c) Using needle–nose pliers, remove the oil seal.

EG–94

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