2001 NISSAN PICK-UP Repair Manual

Trouble Diagnosis of Turbocharger
Preliminary check:
+Check that the engine oil level is between MIN and MAX of
the dipstick. (When the engine oil amount is more than MAX,
the oil flows into the inlet duct through the blow-by gas
passage, and the turbocharger is misjudged failure.)
+Ask the customer if he/she always runs the vehicle in idle
engine speed to cool the oil down after driving.
+Replace the turbocharger assembly when any malfunction is
found after unit inspections specified in the table below.
+If no malfunction is found after the unit inspections, judge that
the turbocharger body has no failure. Check the other parts
again.
Inspection item Inspection resultSymptom (when each inspection item meets each
inspection result)
Oil leakage Smoke NoiseInsufficient
power/
acceleration
failure
Turbine wheelOil leaks.n
nn
Carbon is accumulated.n
jj
Friction with housing.nj
j
Blades are bent or broken.
Compressor wheelInside the air inlet is seriously contaminated
by oil.jj
Friction with housing.njj
Blades are bent or broken.
After checking both turbine and compressor,
inspect rotor shaft end play.There is resistance when the rotor shaft is
rotated by your fingertips.nnj
The rotor shaft sometimes does not rotate
by your fingertips.
There is too much play in the bearing.nnjn
Oil return portCarbon or sludge is accumulated in the
waste oil hole.n
nn
: Large possibility
j: Medium possibility
n: Small possibility
EXHAUST MANIFOLD, TURBOCHARGERYD25DDTi
Inspection (Cont'd)
EM-3044

Removal and Installation
1. Oil filler cap 2. Rocker cover 3. Gasket
PREPARATIVE WORK
Remove the engine following parts.
+Charge air cooler
+Charge air cooler bracket
ROCKER COVER
Removal
Loosen bolts in the reverse order of that shown in the figure and
remove.
Installation
+Tighten bolts in the numerical order shown in the figure.
+Re-tighten to the same torque in the same order as above.
+Apply 3.0 mm (0.118 in) dia. of specified liquid gasket (Refer
to EM-3003, ªLiquid Gasket Application Procedureº.) on loca-
tions shown in the figure.
+Install in the reverse order of removal.
SEM880G
SEM884G
JEM248G
ROCKER COVERYD25DDTi
EM-3045

Components
SEM887G
CYLINDER HEADYD25DDTi
EM-3046

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 cylinder head, camshaft sprocket, crankshaft
pulley, and camshaft bracket.
+Attach tags to valve lifters so as not to mix them up.
Removal
1. Drain engine coolant. Refer to LC section, ªChanging Engine
Coolantº.
2. Remove exhaust manifold, Turbocharger. Refer to EM-3039,
ªRemoval and Installationº.
3. Remove intake manifold. Refer to EM-3035, ªRemoval and
Installationº.
+Apply paint to camshaft sprockets for alignment during
installation.
CAMSHAFT
1. Remove the following parts referring to appropriate part in
this section.
+Charge air cooler cover
+Charge air cooler and charge air cooler bracket
+EGR guide tube and EGR spacer
+Rocker cover
+Spill tube
+Injection tube
+Injection nozzle oil seal
+High pressure injection nozzle assembly
+Secondary timing chain and associated parts
2. Remove camshaft sprockets.
+Holding the hexagonal part of the camshaft with a wrench
having 21 mm (0.83 in) width between facing flats, loosen the
bolt of the camshaft sprocket.
JEM152G
JEM159G
CYLINDER HEADYD25DDTi
Components (Cont'd)
EM-3047

3. Remove camshafts.
+Loosen bolts of the camshaft bracket in several stages in the
reverse order of that shown in the figure, and remove them.
4. Remove adjusting shims and valve lifters.
+Confirm the correct location of each part removed. Store
them so they do not get mixed up.
+For re-installation, be sure to put mark on camshaft
bracket before removal.
CYLINDER HEAD
+Loosen bolts in the reverse order of that shown in the figure
and remove them.
+Be careful not to damage the tips of glow plugs project-
ing out of the bottom surface of the cylinder head. To
avoid damage to glow plugs, either remove them
beforehand, or support cylinder head with wooden
blocks to create a space below the bottom surface.
Disassembly
1. Remove adjusting shims and valve lifters. Confirm the cor-
rect location of each part removed. Store them in order to
avoid mixing them up.
JEM160G
JEM149G
JEM150G
CYLINDER HEADYD25DDTi
Removal (Cont'd)
EM-3048

2. Remove valve collets.
+Compress valve spring with a valve spring compressor, and
remove valve collet with a magnet hand.
3. Remove valve spring retainers, and valve springs.
4. Push valve stem toward combustion chamber and remove valve.
+ Before removing valves, check valve guide clearance. Refer
to EM-3052, ªVALVE GUIDE CLEARANCEº.
+ Confirm the correct location of each valve. Store them so
they do not get mixed up.
+ For the locations and arrangement of intake and exhaust
valves, refer to the figure.
5. Remove valve oil seals.
+ Use a valve oil seal puller (SST) for removal.
6. Remove valve spring seats.
7. When removing valve seats, check valve seat contact. Refer to EM-3053.
8. Before removing valve guides, check valve guide clearance. Refer to EM-3052, ªVALVE GUIDE CLEARANCEº.
9. Remove glow plugs.
+ To avoid damage, glow plugs should be removed only
when required.
+ Handle with care to avoid applying shock. (When
dropped from approx. 100 mm (3.94 in) or higher, always
replace with a new one.)
Inspection
CYLINDER HEAD DISTORTION
Clean surface of cylinder head. Use a reliable straightedge and
feeler gauge to check the flatness of cylinder head surface.
Check along six positions shown in the figure.
Headsurfaceflatness:Limit0.1 mm(0.004 in)
If beyond the specified limit, resurface or replace it.
The limit for cylinder head resurfacing is determined by the
cylinder block resurfacing. Resurfacing limit:Amount of cylinder head resurfacing is ªAº.
JEM151G
JEM152G
JEM153G
SEM496G
CYLINDER HEADYD25DDTi
Disassembly (Cont'd)
EM-3049

Amount of cylinder block resurfacing is ªBº.
The maximum limit:A+B=0.07 mm (0.0028 in)
After resurfacing cylinder head, check that camshaft rotates
freely by hand. If resistance is felt, cylinder head must be
replaced.
Nominal cylinder head height:
153.9 - 154.1 mm (6.059 - 6.067 in)
CAMSHAFT VISUAL CHECK
Check camshaft for scratches, seizure and wear.
CAMSHAFT RUNOUT
1. Place V-blocks on a work bench and support camshaft at No.
1 and No. 5 journal.
2. Set dial gauge perpendicularly at camshaft No. 3 journal.
3. Turn camshaft by hand in one direction and read runout on
dial gauge.
Runout (Total indicator reading):
Limit 0.02 mm (0.0008 in)
4. If it exceeds the limit, replace camshaft.
CAMSHAFT CAM HEIGHT
1. Measure camshaft cam height.
Standard cam height:
Intake
39.505 - 39.695 mm (1.5553 - 1.5628)
Exhaust
39.905 - 40.095 (1.5711 - 1.5785)
Cam wear limit:
0.15 mm (0.0059 in)
2. If wear is beyond the limit, replace camshaft.
CAMSHAFT JOURNAL CLEARANCE
1. Install camshaft bracket and tighten bolts to the specified
torque.
2. Measure inner diameter of camshaft bearing.
Standard inner diameter:
No. 1: 30.500 - 30.521 mm (1.2008 - 1.2016 in)
No. 2, 3, 4, 5: 24.000 - 24.021 mm (0.9449 - 0.9457
in)
JEM161G
SEM549A
JEM162G
CYLINDER HEADYD25DDTi
Inspection (Cont'd)
EM-3050

3. Measure outer diameter of camshaft journal.
Standard outer diameter:
No. 1: 30.435 - 30.455 mm (1.1982 - 1.1990 in)
No. 2, 3, 4, 5: 23.935 - 23.955 mm (0.9423 - 0.9431
in)
4. If clearance exceeds the limit, replace camshaft and/or cyl-
inder head.
Camshaft journal clearance:
Standard
No.1-5:0.045 - 0.086 mm (0.0018 - 0.0034 in)
Limit
0.045 - 0.086 mm (0.0018 - 0.0034 in)
CAMSHAFT END PLAY
1. Install camshaft in cylinder head.
2. Measure camshaft end play.
Camshaft end play:
Standard
0.070 - 0.148 mm (0.0028 - 0.0058 in)
Limit
0.24 mm (0.0094 in)
+If the value exceeds the limit, replace camshaft and measure
again.
+If the measurement exceeds the limit again, replace cylinder
head.
CAMSHAFT SPROCKET RUNOUT
1. Install sprocket on camshaft.
2. Measure camshaft sprocket runout.
Runout (Total indicator reading):
Less than 0.15 mm (0.0059 in)
3. If it exceeds the limit, replace camshaft sprocket.
SEM012A
JEM163G
JEM164G
CYLINDER HEADYD25DDTi
Inspection (Cont'd)
EM-3051