1987 MAZDA 626 low oil pressure

INSTALLATION 1C
Heater Hose
Connect the heater hoses.
Note
Position the hose clamp in the original loca-
tion on the hose and squeeze the clamp lightly
with large pliers to ensure a good fit.
86U01X-221
Connector Location
Install each harness as shown in the figure.
1. Alternator
2. Boost air temperature sensor (RF-CX)
3. Heat gauge unit
4. Water thermo switch
5. Pick up coil
6. Glow cord
7. Front harness connector and ground
76G01C-222
8. Fuel cut valve
9. Oil pressure switch
10. Starter
11. Water temperature switch
12. Transaxle harness
13. Grounds
1C—95

2 A TROUBLESHOOTING GUIDE
SPECIFICATIONS
Engine model Item . FEDOHC F6, F8, FE SOHC
Lubrication system Force-fed
Oil pump
Type Trochoid gear Crescent gear
Oil pump Regulated pressure kPa (kg/cm2, psi) 490 (5.0, 71) 392 (4.0, 57) Oil pump
Oil pressure kPa (kg/cm2, psi)
1,000 rpm 147-245 (1.5-2.5, 21-36) Oil pump
Oil pressure kPa (kg/cm2, psi) 3,000 rpm 343—441 (3.5-4.5, 50-64) 294-392 (3.0-4.0, 43—57)
Oil filter Type Full-flow, paper element Oil filter Relief pressure differential kPa (kg/cm2, psi) 98 (1.0, 14)
Oil cooler Type Water cooled, 6-layer Water cooled, 4-layer
Oil warning pressure kPa (kg/cm2, psi) 29 (0.3, 4.3)
Oil capacity
Total (dry engine) liters (US qt, Imp qt) 4.3 (4.5, 3.8)
Oil capacity Oil pan liters (US qt, Imp qt) 3.6 (3.8, 3.2) Oil capacity
Oil filter liters (US qt, Imp qt) 0.2 (0.21, 0.18) 0.3 (0.32, 0.26)
Engine oil (API service) SD, SE, or SF
76G02A-003
Recommended SAE Viscosity
Temperature j0pj
-30 -20 -10 0 10 20 30 40 50 I l I I 1 < ! I I Temperature j0pj i i i i I i 1 1
-20 0 20 40 60 80 100 120
Engine oil Engine oil
5W-30 X 30 >
Engine oil Engine oil
5W-20 > < 20W-20 > < 40
Engine oil < 10W-30 > Engine oil
< 10W-40 10W-50
Engine oil Engine oil
< 20W-40 20W-50
Engine oil
Temperature range anticipated before next oil change, °C(°F)
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Engine hard
starting
Improper engine oil
Insufficient engine oil
Replace
Add oil
2A— 5
2A— 5
Excessive oil con-
sumption
Oil working up or working down
Oil leakage
Refer to Section 1
Repair
Oil pressure drop Insufficient oil
Oil leakage
Worn or damaged oil pump gear
Worn plunger (inside oil pump) or weak spring
Clogged oil strainer
Excessive main bearing or connecting rod bearing
clearance
Add oil
Repair
Replace
Replace
Clean
Refer to Section 1
2A- 5
2A-11
2A-11
Warning lamp illu-
minated while en-
gine running
Oil pressure drop
Malfunction of oil pressure switch
Malfunction of electrical system
As described above
Refer to Section 15
Refer to Section 15
76G02A-004
2A—4

OIL PUMP 2A
DISASSEMBLY
Disassemble in the sequence shown in the figure. 69G02B-012
1. Pump cover
2. Outer gear
3. Inner gear
4. Pressure relief
valve
5. Oil seal
6. Oil pump body
76G02A-018
INSPECTION
(DOHC)
1. Check the following and replace any faulty parts.
(1) Distorted or damaged oil pump body or cover
(2) Worn or damaged plunger
(3) Weak or broken plunger spring
2. Measure the side clearance.
Clearance: 0.10 mm (0.004 in) max.
76G02A-019
3. Measure the tooth tip clearance.
Clearance: 0.18 mm (0.007 in) max.
69G02B-015
2A-11

OIL PUMP 2 A
76G02A-023
86U02X-022
76G02A-024
5. Measure the outer gear to pump body clearance.
Clearance: 0.20 mm (0.008 in) max.
ASSEMBLY
Assemble the pump as follows.
Oil Seal
1. Apply engine oil to the pump body and the out-
side of the new oil seal.
2. Press in the oil seal.
Pressure Relief Valve
1. Install the plunger and spring in the pump body.
2. Fit the snap ring.
Outer and Inner Gear
Install the gears to the pump body.
Oil Pump Cover
1. Apply thread locking compound to the cover
mounting screws' threads.
2. Attach the oil pump cover to the body.
Tightening torque:
6—9 N-m (60—90 cm-kg, 52—78 in-lb)
INSTALLATION
Install in the reverse order of removal referring to the
installation note.
Installation Note
Oil pump
1. Apply grease to a new O-ring and install it in the
oil pump body.
2. Apply silicon sealant to the shaded area as shown
in the figure.
3. Apply engine oil to the oil seal lip.
76G02A-027
2A-13

2B TROUBLESHOOTING GUIDE
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Engine hard
starting

Improper engine
oil

Insufficient engine
oil

Replace
Add
oil

2B—
6

2B—
5
Excessive oil
consumption

Oil working
up or
working down
Oil leakage
Refer
to
Section
1C

As described below

Oil leakage
Loose drain plug
or
damaged washer
Faulty seal
at oil
pan and cylinder block
Damaged cylinder head cover and
its
seal
Loose
oil
pump body bolt, cylinder head cover bolt,
or

oil pan bolt
Damaged front housing gasket,
or
cylinder head gasket
Faulty
oil
seal(s)
Loose
oil
filter
Loose
or
damaged
oil
pressure switch
Tighten
or
replace
Repair
Replace
Tighten
Replace
Replace
Tighten
Tighten
or
replace
2B—10
2B—10
2B-
6
Oil pressure drop
Oil leakage
Insufficient
oil

Worn and/or damaged
oil
pump gear
Worn plunger (inside
oil
pump)
or
weak spring
Clogged
oil
strainer
Excessive
oil
clearance between main bearing
or
con-
necting
rod
bearing
As described above
Add
oil

Replace
Replace
Clean
Refer
to
Section
1C

2B-
5

2B—13
2B—14

Warning lamp il-
luminates while
engine running

Oil pressure drop
Malfunction
of oil
pressure switch
Malfunction
of
electrical system
As described above
Refer
to
Section
15

Refer
to
Section
15
76G02B-005
2B—4

76G02B-031
76G02B-032
ASSEMBLY
Assemble the pump as follows.
Oil Seal
1. Apply engine oil to the pump body and the out-
side of the new oil seal. 2. Press in the oil seal.
Pressure Relief Valve
1. Install the plunger and spring in the pump body.
2. Install the spring seat plug and tighten to specifi-
cation.
Tightening torque:
26—39 N-m (2.7—4.0 m-kg, 20—29 ft-lb)
Outer and Inner Rotor
Install the rotors with the assembly mark facing the
pump cover.
Oil Pump Cover
1. Apply thread locking compound to the cover
mounting screws' threads.
2. Attach the oil pump cover to the body.
Tightening torque:
6—9 N-m (60—90 cm-kg, 52—78 in-lb)
76G02B-037
INSTALLATION
Install in the reverse order of removal referring to in-
stallation note.
Installation Note
Oil pump
1. Apply grease to a new O-ring and install it in the
oil pump body.
2. Apply silicon sealant to the shaded area as shown
in the figure.
3. Apply engine oil to the oil seal lip.
76G02B-033
2B-14

COOLANT 3A
76G03A-016
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
3A-5

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