Nissan Frontier D40. Instruction — part 572
EM-20
< ON-VEHICLE MAINTENANCE >
[QR25DE]
CAMSHAFT VALVE CLEARANCE
CAMSHAFT VALVE CLEARANCE
Valve Clearance
INFOID:0000000005274267
INSPECTION
Perform the following inspection after removal, installation or replacement of camshaft or valve-related parts,
or if there are unusual engine conditions due to changes in valve clearance over time (starting, idling or noise).
1.
Remove rocker cover. Refer to
EM-36, "Removal and Installation"
.
2.
Remove engine under cover. Refer to
EXT-13, "Removal and Installation"
.
3.
Remove radiator shroud (lower). Refer to
.
4.
Measure the valve clearance as follows:
a.
Set No. 1 cylinder at TDC of its compression stroke.
• Rotate crankshaft pulley clockwise and align TDC mark to tim-
ing indicator on front cover.
• Make sure that intake and exhaust cam noses of No. 1 cylin-
der are located as shown.
• If not, rotate crankshaft one revolution (360
°
) and align as
shown.
b.
Use a feeler gauge to measure the clearance between valve
lifter and camshaft.
Valve clearance:
Unit: mm (in)
*:Approximately 80
°
C (176
°
F)
PBIC3015E
KBIA0400J
SEM139D
Cold
Hot * (reference data)
Intake
0.24 - 0.32 (0.009 - 0.013)
0.304 - 0.416 (0.012 - 0.016)
Exhaust
0.26 - 0.34 (0.010 - 0.013)
0.308 - 0.432 (0.012 - 0.017)
CAMSHAFT VALVE CLEARANCE
EM-21
< ON-VEHICLE MAINTENANCE >
[QR25DE]
C
D
E
F
G
H
I
J
K
L
M
A
EM
N
P
O
• Measure the valve clearances at locations marked “
×
” as
shown in the table below (locations indicated with black arrow
shown) with feeler gauge.
• No. 1 cylinder compression TDC
c.
Rotate crankshaft one revolution (360
°
) and align TDC mark to
timing indicator on front cover.
• Measure the valve clearance at locations marked “
×
” as shown
in the table below (locations indicated with black arrow shown)
with feeler gauge.
• No. 4 cylinder compression TDC
5.
If out of standard, perform adjustment.
ADJUSTMENT
• Perform adjustment depending on selected head thickness of valve lifter.
1.
Measure the valve clearance.
2.
Remove camshaft. Refer to
EM-52, "Removal and Installation"
3.
Remove valve lifters at the locations that are out of the standard.
4.
Measure the center thickness of the removed valve lifters with a
micrometer.
5.
Use the equation below to calculate valve lifter thickness for replacement.
Measuring position
No. 1 CYL.
No. 2 CYL.
No. 3 CYL.
No. 4 CYL.
No. 1 cylinder at
compression TDC
INT
×
×
EXH
×
×
PBIC3017E
PBIC3015E
Measuring position
No. 1 CYL.
No. 2 CYL.
No. 3 CYL.
No. 4 CYL.
No. 4 cylinder at
compression TDC
INT
×
×
EXH
×
×
PBIC3026E
KBIA0057E
EM-22
< ON-VEHICLE MAINTENANCE >
[QR25DE]
CAMSHAFT VALVE CLEARANCE
• Thickness of new valve lifter can be identified by stamp marks
on the reverse side (inside the cylinder).
Stamp mark “696” indicates 6.96 mm (0.2740 in) in thickness.
NOTE:
Available thickness of valve lifter: 26 sizes range 6.96 to 7.46 mm (0.2740 to 0.2937 in) in steps of 0.02
mm (0.0008 in) (when manufactured at factory). Refer to
6.
Install the selected valve lifter.
7.
Install camshaft. Refer to
EM-52, "Removal and Installation"
.
8.
Instructionly rotate crankshaft pulley a few rotations.
9.
Make sure that the valve clearances for cold engine are within specifications by referring to the specified
values.
10. Installation of the remaining components is in the reverse order of removal.
11. Start the engine, and check for unusual noise and vibration.
Valve lifter thickness calculation:
t = t
1
+ (C
1
– C
2
)
t
= Valve lifter thickness to be replaced
t
1
= Removed valve lifter thickness
C
1
= Measured valve clearance
C
2
= Standard valve clearance:
Intake
: 0.28 mm (0.011 in)
Exhaust
: 0.30 mm (0.012 in)
KBIA0119E
COMPRESSION PRESSURE
EM-23
< ON-VEHICLE MAINTENANCE >
[QR25DE]
C
D
E
F
G
H
I
J
K
L
M
A
EM
N
P
O
COMPRESSION PRESSURE
Compression Pressure
INFOID:0000000005274268
CHECKING COMPRESSION PRESSURE
1.
Warm up engine thoroughly.
2.
Release fuel pressure. Refer to
.
3.
Disconnect fuel pump fuse to avoid fuel injection during mea-
surement.
4.
Remove spark plug from each cylinder. Refer to
EM-18, "Removal and Installation"
.
5.
Connect engine tachometer (not required in use of CONSULT-III).
6.
Install compression tester with an adapter into spark plug hole.
• Use the adapter whose pick up end inserted to spark plug hole
is smaller than 20 mm (0.79 in) in diameter. Otherwise, it may
be caught by cylinder head during removal.
7.
With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge
pointer stabilizes, read the compression pressure and the engine rpm. Perform these steps to check each
cylinder.
Compression pressure:
Unit: kPa (kg/cm
2
, psi) /rpm
CAUTION:
Always use fully a charged battery to obtain the specified engine speed.
• If the engine speed is out of the specified range, check battery liquid for proper gravity. Check engine
speed again with normal battery gravity.
BBIA0534E
LBIA0448E
SBIA0533E
Standard
Minimum
Differential limit between cylinders
1,304 (13.3, 189) / 250
1,108 (11.3, 161) / 250
100 (1.0, 14) / 250
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст