coolant MAZDA 626 1987 Service Manual

TROUBLESHOOTING GUIDE
3B

SPECIFICATIONS

Cooling system Water-cooled, forced circulation
Coolant capacity liters (US
qt,
Imp
qt)

With heater 9.5 (10.0, 8.4) Coolant capacity liters (US
qt,
Imp
qt)

Without heater 9.0 (9.5, 7.9)
Water pump Type Centrifugal, timing belt driven Water pump
Water seal Unified mechanical seal
Thermostat
Type Wax, two stage
Thermostat
Opening temperature °C(°F) Main Sub
Thermostat
Opening temperature °C(°F)
86.5-89.5 (188-193) 78.5—81.5 (173-179) Thermostat
Full-open temperature °C(°F) 100 (212) 100 (212)
Thermostat
Full-open lift
mm (in)
8.0 (0.31) min. 1.5 (0.06) min.
Radiator
Type Corrugated
fin

Radiator Cap valve opening pressure
kPa (kg/cm2,
psi)
74-103 (0.75-1.05, 11—15)
Cooling
fan

Type Electric
Cooling
fan

Capacity
W
120
Cooling
fan
Switching temprature orvopi OFF
- ON ^
91 (196) Cooling
fan

Number
of
blade 4
Cooling
fan

Outer diameter
mm
(in) 340 (13.4)

76G03B-003
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Overheating
Insufficient coolant Add 3B-
4

Coolant leakage Repair
—

Radiator fins clogged Clean 3B—
6

Radiator cap malfunction Replace 3B—
5

Cooling fan malfunction Repair 3B-11 Thermostat malfunction Replace 3B—
9

Water passage clogged Clean 3B—
4

Water pump malfunction ReDair
or
replace 3B—
7

Corrosion
Impurities
in
coolant Replace 3B-
4

76G03B-004
3B—3

3B COOLANT
86U03X-004
69G03A-006
COOLANT
INSPECTION
Coolant Level (Engine cold)
1. Check that the coolant level is near the radiator inlet
port.
2. Check that the coolant level in the coolant reser-
voir is between the FULL and Low marks.
Add coolant if necessary.
Warning
a) Never remove the radiator cap while the en-
gine is hot.
b)Wrap a thick cloth around the cap when
removing it.
Coolant Quality
1. Check that there is no build-up of rust or scales
around the radiator cap or radiator filler neck.
2. Check that coolant is free from oil.
3. Replace the coolant, if necessary.
Coolant Leakage
1. Connect a tester and SST to the radiator inlet port.
2. Apply 103 kPa (1.05 kg/cm2, 15 psi) pressure
to the system.
3. Check that the pressure is held.
If not, check for coolant leakage.
Warning
When removing either the radiator cap or the
tester, loosen it slowly until the pressure in
the radiator is released, and then remove it.
86U03X-005
REPLACEMENT
1. Remove the radiator cap and loosen the drain plug.
2. Drain the coolant into a suitable container.
Warning
a) Never open the radiator cap while the en-
gine is hot.
b)Wrap a thick cloth around the cap when
loosening.
c) Use caution when draining hot coolant.
86U03X-006
3B—4

RADIATOR CAP 3B
86U03X-028
86U03X-007
86U03X-008
3. Set the heater control switch to the maximum heat
position.
4. Flush the cooling system with water until all traces
of color are gone, then let the system drain com-
pletely.
5. Fill with the proper mixture and amount of ethy-
lene glycol-based coolant.
Caution
a) Do not use alcohol- or methanol-based
coolant.
b) Use only soft (demineralized) water in the
coolant mixture.
Anti-freeze solution mixture percentage

Protection Volume percentage Gravity
at

20°C (68°F) Protection Solution Water
Gravity
at

20°C (68°F)
Above —16°C (3°F) 35 65 1.054
Above -26°C (-15°F) 45 55 1.066
Above -40°C (-40°F) 55 45 1.078

6. Run the engine at idle with the radiator cap re-
moved. Let any air bleed from the system, and add
more coolant.
7. Install the radiator cap, and inspect all connections
for leakage.
RADIATOR CAP
INSPECTION
Radiator Cap Valve
1. Remove foreign material (such as water residue)
from between the radiator cap valve and the valve
seat.
2. Attach the radiator cap to a tester with the SST.
Apply pressure gradually to 74—103 kPa
(0.75—1.05 kg/cm2, 11—15 psi).
3. Wait about 10 seconds; then check that the pres-
sure has not decreased.
Negative Pressure Valve
1. Pull the negative-pressure valve to open it. Check
that it closes completely when released.
2. Check for damage on the contact surfaces, and
for cracked or deformed seal packing.
3. Replace the radiator cap if necessary.
86U03X-009
3B-5

3B RADIATOR
Note
a) Position the hose clamp in the original location on the hose.
b) Squeeze the clamp lightly with large pliers to ensure a good fit. 86U03X-010
RADIATOR
REMOVAL AND INSTALLATION
1. Drain the engine coolant.
2. Remove in the sequence shown in the figure.
3. Install in the reverse order of removal.
1. Coolant reservoir hose
2. Fast idle solenoid
3. Coolant level sensor connector
4. Cooling fan connector
76G03B-005
5. Upper and lower radiator hose
6. Cooling fan and radiator assembly
7. Cooling fan
INSPECTION
Check the following points. Repair or replace if
necessary.
1. Cracks, damage, or water leakage
2. Bent fins (Repair with a screwdriver)
3. Distorted or bent radiator inlet
86U03X-012
3B-6

WATER PUMP 3B
WATER PUMP
REMOVAL
1. Disconnect the negative battery cable.
2. Turn the crankshaft so that the No. 1 cylinder is at TDC of compression.
3. Drain the engine coolant.
4. Remove in the sequence shown in the figure. 69G03A-025
31—46 N m (3.2—4.7 m-kg, 23—34 ft-lb)
19—26 N-m (1.9—2.6 m-kg, 14—19 ft-lb)
(?) 8—11 N-m (80—110 cm-kg, 69—95 In-lb)
37—52 N-m (3.8—5.3 m-kg, 27—38 ft
55—65 N-m (5.6—6.6 m-kg, 41-48 ft-lb)
(80—110 cm-kg, 69—95 In-lb)
59—69 N-m (6.0—7.0 m-kg, 43—51 ft-lb)
76G03B-006
1. Timing belt (Refer to page 1C—11)
2. Camshaft pulley (Refer to page 1C—36)
3. Injection pump pulley (Refer to page
1C—36)
4. Seal plate
Note
Do not disassemble the water pump body, if a problem is found replace it as a unit.
5. Alternator
6. Water pipe
7. Water hose
8. Water pump body
9. Water pump inlet
3B-7

THERMOSTAT 3B
THERMOSTAT
REMOVAL
1. Drain the engine coolant.
2. Disconnect the upper radiator hose, and water
thermo switch connector.
3. Remove the thermostat cover.
4. Remove the thermostat.
76G03B-010
76G03B-011
Sub valve Main valve
I
INSPECTION
Check the thermostat. Replace if necessary.
1. Visually check that the valve is airtight.
2. Place the thermostat and a thermometer in water.
3. Gradually heat the water and check the following:
Valve opening temperature
Sub valve : 78.5—81.5°C (173—179°F)
Main valve : 86.5—89.5°C (188—193°F)
Full open lift
Sub valve : 1.5 mm (0.06 in) min. at
100°C (212°F)
Main valve : 8 mm (0.31 in) min. at
100°C (212°F)
Valve closing temperature
Sub valve : 75°C (167°F)
Main valve : 83°C
(181
°F)
69G03B-012
76G03B-012
INSTALLATION
1. Install the thermostat into the thermostat case with
jiggle pin at the top.
2. Install a new gasket with the seal print side facing
the thermostat case.
3. Install the thermostat cover.
Tightening torque:
7—10 N-m (70—100 cm-kg, 61—87 in-lb)
4. Install the upper radiator hose and water thermo
switch connector.
5. Replenish the coolant.
6. Start the engine and check for leaks.
3B-9

OUTLINE
4A

Previous

626
Unlead-
ed

fuel
O O O O O O X O O O X

Previous

626

Leaded
fuel
O X X O O X X X O X

New
626
FE
8
Valve
Unlead-
ed

fuel
o O O O O O X X O O O

New
626
Sin-
gapore

o O X O O m O
O

(FE

&
F8)
O
O

(FE

&
F8)
O O

New
626

Middle
East
o X X O O X X X X X O

New
626

General

X
O

(FE

& F8)
X O O X
O

(FE

&
F8)
O

(FE

&
F8)
O

(FE

&
F8)
X o

New
626
ECE
&

Hong
Kong
o O X O O * O O O O O o

Remark
• Adjustment
speed:

2,200

±
100
rpm
(in
neutral).
• MTX • Operation:
Coolant
tempera-

ture

more
than

50°C

(122°F).

Mechanical
type
Installed
on
carburetor.
Improvement
of
product
quality.

Function

Allows

throttle
to
gradually
close

during

deceleration.

Reduces

CO

and
HC
emission.

Detects

electrical
signal
from
in-
put
devices
and
controls
output
devices. Supplies
exhaust
gas
to
intake
manifold
to
reduce
NOx

Filters

fuel

Provides

fuel
to
carburetor.
Detects
when
throttle
valve
fully
closed. Opens
fuel

passage

to
secon-
dary
stage
of
carburetor.
Controls
shutter
valve
by
intake

air
temperature. Prevents
carburetor

icing.

Supplies
fresh
air
to
exhaust
manifold
to
reduce
CO
and
HC
emissions. Prevents
fuel
from
flowing
into

two-way

or
three-way
check

valve

Component

Dashpot Engine
Contorol
Unit

EGR

Control
Valve

Fuel

Filter

Fuel

Pump
Idle
Switch

Idle-up

Solenoid

Valve
Intake
Air
Temperature
Control
Valve

PTC

Heater

Reed

Valve

Separator

•a a> a -a .2-S
3
9-a a) 5 u- O UJ
z

Ox

111 IL •a c x" Ul
V (-
U.ps •o u.
-
X
_ X
I-
o-t-
s ®
s
*
o *
oo
x to
U. UJ
u.
T- oi CO
4 A—13

4 A AUTO-RETURN CHOKE SYSTEM
AUTO-RETURN CHOKE SYSTEM
[FE 8VALVE—UNLEADED FUEL, MIDDLE EAST, and F6—GENERAL]
r ~ I
76G04A-066
An auto-return choke is adopted to prevent the catalytic converter from over-heating because of over
use of the choke. This system opens the choke valve by causing the choke knob to return when the
engine coolant temperature is more than 67°C (153°F).
TROUBLESHOOTING
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting Guide. (Refer to pages 4A—16, 21, or 22)
Possible cause
" ^ Page
Symptom
System inspection Choke magnet Water thermo switch
Possible cause
" ^ Page
Symptom 4A—40 4A—41 4A—41
Checking order 1 2 3
76G04A-067
System Inspection
1. Make sure that the engine is cold and turn the ig-
nition switch ON.
2. Pull out the choke knob and check that it is held on.
3. Start the engine and check that the choke knob
returns during warming-up.
76G04A-068
4A—40

AUTO-RETURN CHOKE SYSTEM 4A
Choke Magnet
1. Remove the under dash cover.
2. Disconnect the choke magnet connector.
3. Turn the ignition switch on and check the resistance
using an ohmmeter.
Resistance: Approx. 3512
4. If it is not within the specification, the choke mag-
net is malfunction.
76G04A-069
76G04A-070
Water thermo switch
1. Remove the switch from the intake manifold.
2. Place the switch in a container of water with a ther-
mometer.
3. Connect an ohmmeter to the switch.
4. Heat the water slowly and check that the switch
has continuity at 67°C (152°F).
5. Replace if necessary.
Note
a) Apply sealing tape to the threads of the
switch.
b) After installing, check the coolant level and
check for leaks.
4A—41

PTC HEATER SYSTEM 4A
System Inspection
Except FE 8Valve—Unleaded Fuel
1. Connect a voltmeter to the PTC heater connector.
2. Start the engine and measure the voltage.
Specification
Radiator coolant
temperature Below 17°C (63°F) Above
17°C (63°F)
Voltage Approx. 12V ov
76G04A-073
FE 8Valve—Unleaded Fuel
1. Start the engine.
2. Connect a voltmeter to the PTC heater connector
terminals and measure the voltage.
Voltage
Engine coolant
temperature
Below 67°C (152°F)
Above 67°C (152°F)
Radiator coolant temperature Below 17°C (63°F) Above 17°C (63°F) —
Terminal BrB Approx.
12V
OV OV Terminal BrW
Approx.
12V Approx. 12V OV
76G04A-074
PTC Heater
Except FE 8Valve—Unleaded Fuel
1. Disconnect the PTC heater connector.
2. Check for continuity of the heater with an
ohmmeter.
76G04A-075
FE 8Valve—Unleaded Fuel
1. Disconnect the PTC heater connector.
2. Check for continuity between terminal wire (BrW)
and a ground.
3. Check for continuity between terminal wire (BrB)
and (B).
76G04A-076
4A—43