1987 NISSAN PULSAR engine coolant

68
COOLING AND HEATING SYSTEMS
SPECIFICATIONS
Coolant capacity ........................................ 6.0 liters
Thermostat:
Opening temperature........................... 91 deg
C

Fully open temperature .................... 103 deg
C

Cooling fan:
Fan cut in temperat ure ....................... 100 deg C
Fan cut out temperature ...................... 95 deg C
Radiator cap opening
pressure ................................................... 78 -98 kPa
TORQUE WRENCH SETTINGS
Water pump retaining bolts .............................25 Nm
Thermostat housing bolts .................................15 Nm
Sender unit .......................................................10 Nm
1. COOLING SYSTEM TROUBLE SHOOTING
COOLANT LEAKAGE - EXTERNAL
(1) Loose hose clips or faulty hoses: Tighten the
hose clips or renew the faulty water hoses.
(2) Leaking radiator core or tanks: Repair or
renew the radiator. (3) Leaking heater core or hoses: Repair or renew the heater core. Check the hose clips and hoses
and renew if necessary.

(4)
Leaks at the thermostat cover and/or water
pump O rings. Renew the O rings. (5) Worn or damaged water pump seal assembly:
Renew the water pump. (6) Worn or damaged water pump bearing as-
sembly: Renew the water pump.
(7) Loose or rusted welch plugs; Renew the
welch plugs. (8) Faulty cylinder head gasket or loose cylinder
head bolts: Renew the cylinder head gasket and
correctly tighten the cylinder head bolts. (9) External crack in the cy linder head or cylin-
der block: Repair or renew the faulty components.
NOTE: Check the system for external leak-
age by running the engine to operating
temperature over a dry floor and checking
for the leak source.

Check the vehicle interior below the
heater core for moisture. If a rusted welch
plug is found, it is a good practice to renew
all the welch plugs.

COOLANT LEAKAGE - INTERNAL
( 1 ) Cylinder head gasket leak due to warped
cylinder head or cylinder block gasket faces: Reface


Checking the radiator hose for deterioration.

Check the engine oil for level and dilution on the
dipstick.

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.

Cooling and Heating Systems 71

TO DRAIN AND REFILL
(1) Place a drain tin under the radiator drain
plug.
(2) Switch the heater controls to the maximum
heat position. (3) Remove the radiator cap and open the
radiator drain plug.
(4) Disconnect the reserve tank hose from the
radiator filler neck. (5) Lower the end of the hose and drain the
coolant from the reserve tank. (6) After all the coolant has drained from the
cooling system, install the radiator drain plug
ensuring
that the plug seal is in good condition. (7) Disconnect the wire from the temperature
sender switch and remove the switch using a suitable
spanner.
(8) Using a clean container, mix Nissan long life
coolant with clean soft water to the proportions
stipulated on the coolant container.
(9) Slowly pour the premixed coolant into the
radiator until the radiator is full and all air has
escaped through the temperat ure sender switch hole.
Install the radiator cap. (10) Fill the coolant reserve tank to the Maxi-
mum mark.
(11) Start the engine and allow it to idle.
(12) When coolant starts to flow through the
temperature sender switch hole, install the temperature
sender switch and tighten securely. (13) Continue idling the engine until the cooling
fan is activated.
(14) Switch the engine off and allow it to cool.
(15) Refill the radiator using coolant and install
the radiator cap.

Dismantled view of the radiator and associated components. Automatic transaxle model with
air conditioning.

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.

Cooling and Heating Systems 73
(1) Renew all hoses that show signs of cracking
or perishing.
(2) Before finally tightening the hose clips, en-
sure that the hoses are push ed fully onto the radiator
and are not kinked. (3) On automatic transaxle models, ensure that
the oil cooler hoses are correctly installed to the
radiator and show no signs of leakage. Check and top
up the automatic transaxle fluid as necessary.
5. COOLING FAN
The radiator cooling fan is controlled by the
electronic control unit, and on vehicles with air
conditioning, the condenser fan relay. On vehicles
with air conditioning there are two cooling fans, one
is larger than the other. The large fan is for the
radiator and the smaller fan provides extra cooling
when the air conditioning is activated. Each fan is
controlled by a separate system.

TO TEST COOLING FAN AND SYSTEM
(1) With the cooling system cold and the air
conditioning, if applicable, switched off, switch the
ignition On and confirm that the cooling fan is
stationary.

NOTE: Leave the ignition On for all tests
unless otherwise stated.

(2) In the above test, if the cooling fan rotates,
proceed as follows:

(a) Disconnect the cooling fan relay from the
rear of the engine compartment relay box.
(b) If the fan stops, backprobe terminal C1 at
the electronic control unit using an LED test lamp
connected to the positive battery terminal. If no
circuit exists, renew the cooling fan relay.

View showing the location of the diagnostic link
connector. Passengers seat removed for clarity.
If a circuit exists, check the wiring harness
between the electronic control unit and the relay for
short circuits to earth and repair if necessary. If no
short circuit is present renew the electronic control
unit.


Schematic layout of the cooling fan, coolant temper-
ature sensor and related electrical components.

Installed view of the engine compartment relays. KEY

1. To Battery
2. Fusible link
COLOUR CODE
3. Fusible link
B-Black
4. Fusible linkL- Blue
5. I
gnition relayY- Yellow
6. Fuse 20 am
pW-White
7. Coolin
g fan relayO-Orange
8. Coolin
g fan
9. Coolant tem
perature
sensor
10. To air conditionin
g
fan rela
y
11. To throttle
position
sensor
12. Control unit

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.

Cooling and Heating Systems 75
(4) Remove the bolts retaining the fan shroud
assembly to the radiator and carefully move the
shroud assembly upwards and towards the engine to
release it from the lower mountings.

NOTE: On models with air conditioning, it
will be necessary to hold the air conditioning
compressor hoses toward s the engine to
allow clearance for removal of the shroud
assembly.

(5) If necessary, remove the fan from the fan
motor by removing the retaining bolts or on some
models the nut and washers.
(6) If necessary, remove the fan motor from the
shroud assembly by removing the retaining bolts or
nuts. Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure all the fan motor and fan retaining
nuts and bolts are tightened securely. (2) Ensure that all the rubber mountings are in
good condition. Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure that all sealing surfaces are clean.
(2) Renew the O ring on installation.
(3) Tighten the thermostat cover retaining bolts
securely.
(4) Fill the cooling system as previously de-
scribed ensuring that the heater control lever is in the
maximum heat position. Check for coolant leaks.
TO CHECK

NOTE: A visual examination of the thermo-
stat will often determine its serviceability
and make further testing unnecessary. For
instance, a thermostat with its valve fully-
open when removed from a cold engine is
obviously faulty and should be renewed.

Remove the thermostat from the thermostat
6. THERMOSTAT
Special Equipment Required:
To Check — Thermometer

TO REMOVE AND INSTAL
(1) Drain the cooling system as previously de-
scribed under the Radiator heading.
(2) On 1.6 liter models, remove the air cleaner
assembly. Refer to the Fuel and Engine Management
section if necessary. (3) Disconnect the top radiator hose from the
thermostat cover.
(4) Remove the bolts retaining the thermostat
cover to the thermostat housing. (5) Remove the thermostat cover, thermostat
and O ring from the thermostat housing.
NOTE: The thermostat and cover are ser-
viced as a unit and cannot be renewed
separately.


View of the thermostat removed from the vehicle and dismantled for testing. Line drawing showing the correct method to test the
thermostat.

(4) Progressively heat the mixture noting the
temperature reading on the thermometer as the ther-
mostat valve commences to open and when it is fully
open.

See the Specifications for opening and fully open
temperatures.

A thermostat which is not opening or is not open
at the specified temperatures should be renewed.