Isuzu Rodeo UE. Service manual - part 286

6A–57

ENGINE MECHANICAL (6VD1 3.2L)

1. Measure the valve stem diameter with a micrometer.

If the valve stem diameter is less than the specified
limit, the valve and the valve guide must be replaced
as a set.

Diameter of Valve Stem
Intake
Standard : 5.977 mm–5.959 mm

(0.2353 in–0.2346 in)

Limit : 5.90 mm (0.2323 in)
Exhaust
Standard : 5.952 mm–5.970 mm

(0.2343 in–0.2350 in)

Limit : 5.90 mm (0.2323 in)

014RS007

2. Measure the inside diameter of the valve guide with a

micrometer. Subtract the measured outer diameter of
the valve stem from the measured inner diameter of
the valve guide. If the value exceeds the specified
limit, the valve and the valve guide must be replaced
as a set.

Inside Diameter of the Vale Guide
Inlet clearance
Standard : 0.023 mm–0.056 mm

(0.0009 in–0.0002 in)

Limit : 0.20 mm (0.00787 in)
Exhaust clearance
Standard : 0.030 mm–0.063 mm

(0.0012 in–0.0025 in)

Limit : 0.20 mm (0.00787 in)

Valve Guide Replacement

1. Using Valve guide replacer: J–42899, drive out the

valve guide from the combustion chamber side.

014RS008

2. Apply engine oil to the outside of the valve guide.

Using valve guide replacer J–42899, drive in a new
valve guide from the camshaft side, and check the
valve guide height.

Valve guide upper end height: 13.0 mm (0.5118
in)

(Measured from the cylinder head upper face)

014RW046

3. Check the clearance. If the clearance is less than the

specified value, ream the inside diameter of valve
guide. Using a sharp 6 mm reamer, ream the valve
guide to obtain the specified clearance.

6A–58

ENGINE MECHANICAL (6VD1 3.2L)

Valve Seat

1. Measure the protrusion of the valve stem when a new

valve is installed in the cylinder head. If the protrusion
of the valve stem exceeds the limit, replace the valve
seat insert or the cylinder head assembly.

Protrusion of valve stem
Intake
Standard: 39.32 mm (1.5480 in)
Limit: 39.47 mm (1.5539 in)
Exhaust
Standard: 39.3 mm (1.5472 in)
Limit: 39.45 mm (1.5531 in)

014RW047

2. Measure the valve seat contact width. Make the

necessary corrections if the seat contact surface is
damaged or rough or if the contact width wear
exceeds the limit.

Valve seat contact width
Standard: 1.1 mm (0.0433 in)
Limit: 1.7 mm (0.0669 in)

014RS011

Contact Surface Angle on Valve Seat on
Valve

1. Measure contact surface angle on valve seat.
2. If the measured value exceeds the limit, replace

valve, valve guide and valve seat as a set.

Valve contact surface angle: 45

°

014RS012

Valve Seat Insert Correction

1. Remove the carbon from the valve seat insert

surface.

2. Use a valve cutter to minimize scratches and other

rough areas. This will bring the contact width back to
the standard value. Remove only the scratches and
rough areas. Do not cut away too much. Take care not
to cut away unblemished areas of the valve seat
surface.

Valve seat angle degree: 90

°

014RW059

6A–59

ENGINE MECHANICAL (6VD1 3.2L)

3. Apply abrasive compound to the valve seat insert

surface.

4. Insert the valve into the valve guide.
5. Turn the valve while lapping it to fit the valve seat

insert.

6. Check that the valve contact width is correct.
7. Check that the valve seat insert surface is in contact

with the entire circumference of the valve.

014RS014

Valve Seat Insert Replacement

1. Arc weld the rod at several points. Be careful not to

damage the aluminum section.

2. Allow the rod to cool for a few minutes. This will cause

the valve seat to shrink.

3. Strike the rod and pull it out.

014RS015

4. Carefully clean the valve seat press–fit section on the

cylinder head side.

5. Heat the press–fit section with steam or some other

means to cause expansion. Cool the valve seat with
dry ice or some other means.

6. Insert the press–fit section into the valve seat

horizontally.

Standard fitting interference: 0.14 mm–0.09 mm
(0.0055 in–0.0035 in)

7. After insertion, use a seat grinder to grind finish the

seating face. Carefully note the seating angle, the
contact width, and the depression.

8. Lap the valve and the seat.

Reassembly

1. Install valve guide (1) to cylinder head. Apply engine

oil to the outside of the valve guide. Using valve guide
replacer J–42899, drive in a new valve guide from the
camshaft side.

2. Install oil controller (3) and spring lower seat (2).

Using oil controller replacer J–37281, drive in a new
oil controller.

014RW058

6A–60

ENGINE MECHANICAL (6VD1 3.2L)

3. Install valve to valve guide. Before install valve guide

apply engine oil to the outside of the valve stem.

4. Install valve spring to cylinder head. Attach the valve

spring to the lower spring seat. The painted area of
the valve spring should be facing downward.

014RS020

5. Install lower valve spring seat, valve spring and upper

valve spring seat then put split collars on the upper
spring seat, using the J–8062 valve spring compresor
and J–42898 valve spring compressor adapter to
install the split collars.

014RW042

6. Install tappet with shim.
7. Install camshaft assembly.

f

Refer to installation procedure for Camshaft in this
manual.

Valve Clearance Adjustments

NOTE: To adjust valve clearance, apply engine oil to the
cam as well as to the adjusting shim (2) with the cylinder
head built on the cylinder block, give a few turns to the
camshaft by means of timing pulley tightening bolt, and
measure valve clearance when the nose of cam is just
opposite to maximum cam lift (1) as shown in illustration
below.

014RW081

Legend

(1) Cam
(2) Shim
(3) Tappet

Valve Clearance Standard Value (cold)

Intake: 0.23 mm–0.33 mm

(0.0091 in–0.0130 in)

Exhaust: 0.25 mm–0.35 mm

(0.0098 in–0.0138 in)