1987 NISSAN PULSAR engine overheat

Engine 39
Oil pump cover plate screws............................ 6 Nm
Oil pump mounting bolts.................................. 6 Nm
Oil pump pickup bolts
(coat with Loctite 242)..................................... 8 Nm
Sump bolts (coat with Loctite 242) .................. 5 Nm
Sump drain plug .............................................. 35 Nm
*Use new bolts
Head bolts maximum torque 135 Nm

1. ENGINE MECHANICAL TROUBLE
SHOOTING

ENGINE MISSES AT IDLING SPEED
NOTE: For other causes of engine misfire,
refer to the Fuel and Engine Management
section.

(1) Blown head gasket: Check the cylinder com-
pressions and renew the he ad gasket as necessary.
(2) Burnt valves or seats in the cylinder head:
Check the cylinder compressions and overhaul the
cylinder head as necessary. (3) Broken or worn piston rings: Check the
cylinder compressions and renew the piston rings as
necessary.
(4) Weak or broken valve springs: Remove the
camshaft housing top cover and check the condition
of the valve springs. (5) Air leak at the inlet manifold gasket; Check
for air leaks by applying oil around the manifold
joints. Renew the gasket if an air leak is evident.
NOTE: Use a compre ssion gauge and check
the compression pressure in each cylinder as
described in the Engine Tune-up section. If
a low pressure reading is indicated in one or
more cylinders, remove the cylinder head for
gasket and valve inspection. Should the


gasket and valves prove satisfactory, inspect
the cylinder bores, pistons and rings.

Check for air leaks at the inlet manifold
by applying engine oil around the manifold
joints. If the oil can be seen or heard sucking
into the manifold or excessive smoke begins
to issue from the exhaust system, there is an
air leak at the inlet manifold.

NOISY VALVE OPERATION
(1) Faulty hydraulic tappets: Renew the faulty
tappet assemblies. (2) Weak or broken valve springs: Remove the
camshaft housing top cover and check the condition
of the valve springs. (3) Worn valve guides: Overhaul the cylinder
head as described in this section. (4) Worn rocker gear: Remove (he rocker gear
and check the components for wear.

Camshaft lobe wear is also a cause of noisy valve
operation.
BIG END BEARING NOISE
(1) Inadequate oil supply: Check the oil level in
the sump and the condition of the oil pump and relief
valve. Renew the oil filter.

(2) Excessive bearing clearance: Renew the bear-
ing shells, check and regrind the big end journals if
oval or tapered. (3) Thin oil or oil diluted by petrol or water:
Change to the correct oil grade. Check and rectify the
cause of the oil dilution. Ch eck that the engine is not
operating in overheat conditions.
(4) Low oil pressure: Check the engine oil level.
Check the pressure relief valve and spring and the oil
filter bypass valve. (5) Misaligned big end bearings: Align the con-
necting rods and renew the big end bearing shells.
NOTE: Big end bearing noise is indicated
by a metallic knock wh ich is usually loudest
at approximately 60 km/h with the throttle
Air leaks at the inlet manifold can be located by
applying engine oil around the suspect joints.

Engine 41

DROP IN OIL PRESSURE
(1) Oil level low in the sump: Check and replen-
ish the oil to the full mark on the dipstick.
(2) Thin or diluted oil: Change to the correct oil
grade and rectify the source of dilution. (3) Oil pump relief valve stuck or spring broken;
Free up the relief valve or renew the broken relief
valve spring. (4) Excessive bearing clearance: Renew the bear-
ing shells or recondition the crankshaft journals as
necessary.
(5) Excessive wear of the oil pump components:
Renew or recondition the oil pump.
NOTE: If the vehicle is not equipped with an
oil pressure gauge re move the oil sender unit
and connect a pressure gauge into the oil
gallery. Check the oil pressure with the
engine cold and hot. If the oil pump or relief
valve are faulty. low pressure will be indi-
cated with the engine both hot and cold.
However, if the bearings are at fault a fairly
high oil pressure will be indicated when the
engine is cold, but a marked drop in pressure
will occur when the engine is hot.

ENGINE WILL NOT ROTATE
(1) Starter motor drive jammed: Remove the
starter motor. Check and renew the damaged drive
and/or flywheel ring gear.
(2) Engine overheated an d seized: Remove and
dismantle the engine. Check and renew any damaged
components. See the following note.
(3) Water in the cylinder due to a blown head
gasket or cracked cylinder block or head: Remove the
cylinder head. If the gasket is blown, check for
cylinder block and head distortion and reface if
necessary. Renew the cylinder head and/or cylinder
block if cracked.
(4) Broken crankshaft, connecting rod. piston
etc. due to overheating, fatigue etc: Remove and
dismantle the engine. Examine and renew any com-
ponents as necessary. (5) Valve head broken off due to overheating,
fatigue etc: Remove the cylinder head and check the
head, piston and cylinder bore for damage. Repair or
renew as necessary.
NOTE: Invariably when an engine seizes
because of overheating due to lack of oil
and/or water, damage is done to the bear-
ings, pistons etc. Although there may be
instances where an engine will start and run
after it has cooled down and the oil and
water have been replenished, it will usually
be found that oil consumption increases, oil
pressure decreases and the engine will be
noisier, depending on the degree of damage.

When a cylinder head gasket blows allow-
ing water into the cylinders, or compression
loss between the cylinders, it is essential to
check the gasket faces on the cylinder block
and head for distortion. Sufficient water can
enter a cylinder because of a blown head
gasket, cracked cylinder or head to prevent
an engine from rotating.

This is normally preceded by difficult
starting, misfiring, excessive steam from the
exhaust and loss of water from the radiator.

Frequent jamming of the starter motor
drive with the flywheel ring gear can be due
to a bent starter armature shaft or damaged
teeth on the drive and/or ring gear. With the
starter motor removed, the flywheel ring
gear teeth can be examined through the
starter motor mounting aperture. Renewal
of the ring gear requires removal of the
transaxle, clutch and flywheel on manual
transaxle models and the removal of the
transaxle and drive plate on automatic
transaxle models. To check for a bent arma-
ture shaft, rotate the shaft by hand while
holding the end in close proximity to a fixed
object.

2. DESCRIPTION
The 1.6 and 1.8 liter engines are basically identi-
cal in design.

Both engines share the same stroke. The 1.8 liter
engine has a larger bore thus giving it increased
capacity.

The engine is a four cylinder, inline, overhead
camshaft design transversely mounted in the front of
the vehicle.

The camshaft runs in five integral support bear-
ings in the camshaft housing which in turn is mounted
directly on to the cylinder head and retained by the
cylinder head bolts.

Camshaft end float is controlled by a retaining
plate engaged in a groove machined in the rear
camshaft journal. The camshaft is driven by the
crankshaft timing gear vi a a reinforced rubber belt.

The aluminum cross flow cylinder head houses
the tappets, rocker arms a nd valve assemblies. An oil
pressure relief valve is installed to the cylinder head to
maintain oil pressure to the hydraulic tappets at a
predetermined setting.

The exhaust valve springs are equipped with
rotators mounted below the valve springs which rotate
the exhaust valve assemblies. The rocker arms pivot
on hydraulic tappet assemblies and locate in notched
lash pads mounted on the valve stems. The camshaft
lobes bear directly onto the rocker arms and due to
the characteristics of the hydraulic tappet assemblies,
no provision is made for tappet clearance adjustment.

Cooling and Heating Systems 69

the cylinder head or cylinder block and renew the
cylinder head gasket.

(2) Crack in the cylinder head or cylinder block:
Repair or renew as necessary.

NOTE; Check the engine for internal leak-
age by withdrawing the dipstick and inspect-
ing for emulsified oil. Run the engine and
check for excessive steam at the exhaust
pipe which would indi cate coolant leakage
into the combustion chamber.

COOLANT LOSS BY OVERFLOW
(1) Overfull system: Drain the excess coolant
from the system.
(2) Faulty radiator cap: Renew the faulty cap.
(3) Blocked radiator core tubes: Clean or renew
the radiator core.

(4) Faulty thermostat: Renew the thermostat.
(5) Coolant foaming due to poor quality anti-
freeze or corrosion inhibitor: Drain the system and
renew the coolant and additive.

Renew the radiator cap if the sealing rubber has
deteriorated.
ENGINE OVERHEATING
(1) Radiator cap defective: Renew the radiator
cap.
(2) Incorrect fuel mixture: Check the fuel system
as described in the Fuel and Engine Management
section. (3) Obstructed air passage through the radiator
core from the front to the rear: Blow the obstruction
from the rear to the front of the radiator core using
compressed air or water pressure. (4) Faulty thermostat: Renew the thermostat.
(5) Incorrect ignition timing: Check and adjust
the ignition timing as described in the Engine Tune-up
section. (6) Incorrect valve timing: Set the valve timing
as described in th e Engine section.
(7) Loss of coolant from the overflow: Check
and rectify as described under the heading Coolant
Loss By Overflow.
(8) Poor circulation: Check and rectify as de-
scribed under the heading Coolant Circulation Faulty.
(9) Low engine oil level: Stop the engine imme-
diately and replenish the oil in the sump. (10) Restricted muffler, catalytic converter or
damaged tailpipe, accompanied by loss of power:
Remove the restrictions or renew the faulty com-
ponents as necessary.
(11) Incorrectly adjusted or dragging brakes:
Check and rectify by adjustment or renewal of
components. (12) Faulty temperature gauge and/or sender unit:
Check and rectify as necessary.
NOTE: Engine overheating is indicated by
an excessive rise in engine temperature
shown by the temperature gauge.

Overheating is usually accompanied by
steam emitting from the coolant overflow
pipe and loss of engine power. A blown
cylinder head gasket may be indicated by
bubbles in the coolant.

COOLANT CIRCULATION FAULTY
(1) Partial blockage of the radiator core tubes:
reverse flush or renew the radiator core.
(2) Sludge deposits in the engine water jacket:
Clean and flush the engine water jacket and add
inhibitor to the coolant. (3) Faulty water pump: Renew the water pump.
(4) Faulty thermostat: Renew the thermostat.
(5) Collapsing lower radiator hose: Renew the
lower radiator hose and check the radiator core tubes. (6) Insufficient coolant in the system: Replenish
the coolant and check for leaks.
NOTE: If rust or sludge deposits are sus-
pected, check the color of the coolant in the
radiator. Rusty or muddy coolant indicates
rust or sludge in the system.

2. HEATER AND AIR CONDITIONER TROUBLE SHOOTING

NO HOT AIR INSIDE VEHICLE
Faulty thermostat: Renew the thermostat.
Faulty heater valve: Check and renew the

Blocked heater hoses: Remove the blockage.
Blocked heater core: Clean or renew the core.

NOTE: Ensure that the engine is reaching
normal operating temperature. If in doubt
check the operation of the thermostat as
described under the Thermostat heading in
this section.

(1)
(2)
valve.
(3)
(4)

70 Cooling and Heating Systems


Installed view of the heater hoses. 1.6 liter models with the air cleaner removed for clarity
.
When the engine is at normal operating
temperature and the heater valve is open,
both of the heater hoses should feel
warm/hot. If the valve is not allowing the
coolant to flow, one hose will be hot while
the other will be cold.

NO COOLED AIR INSIDE VEHICLE
(1) Compressor drive belt slipping or broken:
Renew and/or adjust the drive belt as described in the
Engine Tune-up section.
(2) Insufficient refrigerant: Check the system for
leaks and charge as necessary. Refer to the Air
Conditioning heading in th is section for information
on checking the refrigerant level. (3) Compressor inoperative: Check for power to
the compressor clutch before removing the compres-
sor for repair by a specialist. (4) Heater system allowing warm air to mix with
cooled air: Check the operation of the heater system.
NOTE: The above trouble shooting proce-
dures are basic checks only. If the air
conditioning system is suspect, it is rec-
ommended that the vehicle be taken to an
authorized dealer for testing and repair.
It is normal for water to be seen drain-
ing under the vehicle from the evaporator
after the vehicle has been operated with
the air conditioning on.

3. DESCRIPTION
The cooling system is of the sealed, pressurized
type with fan and water pump assistance. The system
is pressurized in order to raise the boiling point of the
coolant and so increase the efficiency of the engine.

Provision for pressure a nd vacuum relief of the
system is incorporated in the radiator cap.

The radiator overflow hose is connected to a
reserve tank mounted adjacent to the battery. As the
coolant volume expands due to an increase in tem-
perature, the pressure valve in the radiator cap opens
and allows the excess coolant to flow into the reserve
tank. When the engine is stopped and the temperature
of the coolant falls, the vacuum valve in the radiator
cap opens and allows the excess coolant in the reserve
tank to siphon back into the radiator. Thus the
necessity for frequent topping up of the coolant is
eliminated.

The temperature of the cooling system is con-
trolled by a thermostat located in the thermostat
housing attached to the cylinder head.

The thermostat prevents circulation of coolant
through the radiator by directing coolant through the
by-pass circuit, until the engine has reached operating
temperature. This restricted circulation allows the
engine to reach operating temperature quickly, im-
proving drivability and fuel economy.

Removal of the thermostat to cure overheating is
not recommended because th e by-pass circuit will
remain open reducing the amount of water flowing
through the radiator.

An anti-corrosion inhibitor should always be
added to the coolant to protect the cooling and
heating systems from corrosion.

The water pump is mounted to the front of the
engine and is driven by the camshaft drive belt. It is
equipped with a double row ball bearing and a spring
loaded seal assembly. The water pump is a disposable
unit and cannot be repaired.

The fan is driven by an electric motor which is
actuated by the coolant temperature sensor and the
control unit.

On vehicles equipped with air conditioning, an
additional electric fan is m ounted to the radiator. This
fan is controlled by a sw itch connected to the air
conditioning compressor.

The radiator consists of an aluminum core with
plastic side tanks. Minor damage to the core can be
repaired using Nissan repair agent.

The left hand tank of the radiator houses the
transaxle oil cooler on automatic transaxle models.

To drain the cooling system a drain plug is
provided on the lower radiator pipe outlet.

4. RADIATOR
NOTE: To avoid scalding, use caution when
releasing the radiator cap on an engine
which is at the normal operating tempera-
ture. Turn the cap anti-clockwise to the first
stop and allow any pressure in the system to
release. When the pressure is released turn
the cap past the stop and remove it from the
radiator.

72 Cooling and Heating Systems

(16) After the vehicle has been driven several
kilometers check the coolant level in the reserve tank
and top up if necessary.

TO REMOVE
(1) Drain the cooling system as previously de-
scribed.
(2) Loosen the hose clamps and disconnect the
hoses from the radiator. (3) If applicable disconnect the automatic trans-
axle oil cooler hoses from the left hand side radiator
tank. Plug the hoses and fitt ings to prevent the entry
of dirt and the loss of fluid.
(4) Disconnect the hose from the reserve tank at
the top of the radiator. (5) On models with air conditioning, remove the
hoses and support bracket bolts and move the bracket
and hoses away from the top of the radiator. (6) Remove the radiator support bracket bolts
from the radiator support pa nel and lift the radiator
from the lower mountings and out of the vehicle.
NOTE: A radiator that has been in use for
some time should not be allowed to stand
empty for any length of time. The radiator
should be immersed in a tank of coolant or
otherwise kept full. If applicable, ensure that
no coolant is allowed to enter the automatic
transaxle oil cooler in the left hand side tank
of the radiator.

Failure to observe this precaution may
result in overheating when the engine is put
back into service. This is caused by internal
deposits in the radiator drying and flaking
and so obstructing the circulation of the
coolant in the system.

TO FLUSH AND CLEAN
(1) Remove the radiator as previously described.
(2) Apply a water hose to the radiator outlet and
reverse flush the radiator until the water flowing from
it is clean.

Cleaning the radiator core from the rear to the front
using a garden hose.
(3) Stand the radiator upright and apply a
stream of water or compressed air to the radiator core
from the rear to [he front. Maintain this procedure
until all dirt and foreign matter is removed from the
radiator core.
(4) With the aid of a light, make a visual check
of the core tubes through the radiator inlet or outlet
fittings. If it is apparent that the tubes are severely
impregnated with flakes of rust it will be necessary to
renew the radiator assembly.
TO REPAIR

The repair procedure described below is only
suitable for holes occurring in the radiator core tubes
that are not bigger than approximately 1 mm.

(1) Suitably mark the area of the leak using a
piece of chalk or similar. (2) Remove the radiator from the vehicle as
previously described, clean it thoroughly and dry the
damaged area with a hair dryer. (3) If necessary, carefully cut away or bend the
fins from the tubes to expose the affected area.
NOTE: Do not remove more than 25 mm
total finning from the radiator or cooling
performance will be affected.

(4) Clean the damaged area carefully using a
scraper and wipe clean using a cloth moistened with
petrol.
(5) Apply well mixed Nissan or Holden adhe-
sive part number 21411-J7025, or equivalent, spar-
ingly to the damaged area using a wooden spatula.
(6) Allow the repair to dry in ambient condi-
tions for a minimum of 3 hours before installing the
radiator to the vehicle and testing for leaks. Do not
use heat to promote drying.
TO INSTAL

Installation is a reversal of the removal procedure
with attention to the following points:
Reverse flushing the radiator using water pressure.

74 Cooling and Heating Systems
NOTE: Refer to the Fuel and Engine Man-
agement section for the correct procedure for
backprobing the control unit.

(3) In operation (1) if the cooling fan is station-
ary proceed as follows:

(a) Connect a jumper lead between the terminals
A and B of the diagnostic link connector. (b) if the fan runs, the fan circuit is satisfactory.
If the engine is overheating check the coolant temper-
ature sensor as described in the Fuel and Engine
Management section under the appropriate codes. (c) If the fan does not run, check the fuse (6) and
the fusible link (4) show n on the illustration.
(d) Backprobe terminal C1 at the electronic
control unit using an LED t est lamp connected to the
positive battery terminal. If no circuit exists, renew
the electronic control unit. (e) If the fuse and fusible links are serviceable,
ensure that power is available at the white and pink
wires from the fuse and fusible link of the cooling fan
relay. Repair any faults in the wiring to that point if
necessary. (f) Switch the ignition Off. disconnect the
cooling fan wiring connector at the radiator and
connect power to the fan. Renew the fan if it does not
run.

(4) On air conditioned models, remove the
jumper lead from the ALDL connector if still in-
stalled, start the engine and allow it to idle. Switch the
air conditioning on and ensu re that the cooling fan
runs.

If the cooling fan is opera ting as described above
but cooling system problems still exist, refer to the
Trouble Shooting heading at the start of this section.

TO REMOVE AND INSTAL COOLING FAN
(1) Disconnect the negative battery terminal.
(2) Disconnect the cooling fa n and, if applicable,
the air conditioning fan wiring connectors at the
upper edge of the radiator. (3) On models with air conditioning, remove the
compressor hose bracket bolt from the centre of the
radiator support panel.

Dismantled view of the fans and the shroud assembly. Air conditioned model.