Nissan Frontier D40. Manual — part 187
OVERHEATING CAUSE ANALYSIS
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< FUNCTION DIAGNOSIS >
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OVERHEATING CAUSE ANALYSIS
Troubleshooting Chart
INFOID:0000000005276082
Symptom
Check items
Cooling sys-
tem parts
malfunction
Poor heat transfer
Water pump malfunction
Worn or loose drive belt
—
Thermostat and water con-
trol valve stuck closed
Thermostat or water control
valve
Damaged fins
Dust contamination or pa-
per clogging
Physical damage
Clogged radiator cooling
tube
Excess foreign material
(rust, dirt, sand, etc.)
Reduced air flow
Cooling fan does not oper-
ate
Fan assembly
—
High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud
—
Radiator shroud
—
Improper engine coolant
mixture ratio
—
Engine coolant viscosity
—
Poor engine coolant quality
—
—
Insufficient engine coolant
Engine coolant leaks
Cooling hose
Loose clamp
Cracked hose
Water pump
Poor sealing
Radiator cap
Loose
Poor sealing
Radiator
O-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank
Cracked reservoir tank
Overflowing reservoir tank
Exhaust gas leaks into cool-
ing system
Cylinder head deterioration
Cylinder head gasket deteri-
oration
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OVERHEATING CAUSE ANALYSIS
Except cool-
ing system
parts mal-
function
—
Overload on engine
Abusive driving
High engine rpm under no
load
Driving in low gear for ex-
tended time
Driving at extremely high
speed
Power train system mal-
function
—
Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flow
Blocked bumper
Mud contamination or paper
clogging
—
Blocked radiator grille
Installed car brassiere
Mud contamination or paper
clogging
Blocked radiator
Blocked air flow
Blocked condenser
Installed large fog lamp
Symptom
Check items
ENGINE COOLANT
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ON-VEHICLE MAINTENANCE
ENGINE COOLANT
System Inspection
INFOID:0000000005276083
WARNING:
• Never remove the radiator cap or reservoir tank cap when the engine is hot. Serious burns could
occur from high pressure fluid escaping from the radiator or reservoir.
• Wrap a thick cloth around the cap. Slowly push down and turn it a quarter turn to allow built-up pres-
sure to escape. Carefully remove the cap by pushing down and turning it all the way.
CHECKING COOLING SYSTEM HOSES
Check hoses for the following:
• Improper attachment
• Leaks
• Cracks
• Damage
• Loose connections
• Chafing
• Deterioration
CHECKING RESERVOIR LEVEL
• Check if the engine coolant reservoir tank level is within MIN to
MAX when the engine is cool.
• Adjust engine coolant level as necessary.
CHECKING COOLING SYSTEM FOR LEAKS
WARNING:
Never remove the radiator cap or reservoir cap when the engine is hot. Serious burns could occur
from high pressure coolant escaping from the radiator or reservoir.
• To check for leakage, apply pressure to the cooling system at the
reservoir filler neck using suitable tool and Tool.
CAUTION:
Higher pressure than specified may cause radiator damage.
NOTE:
In case that engine coolant decreases, replenish cooling system
with engine coolant.
• If any concerns are found, repair or replace damaged parts.
CHECKING RESERVOIR CAP
1.
Inspect the reservoir cap.
• Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.
• Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or
the metal retainer.
NOTE:
Thoroughly wipe out the reservoir filler neck to remove any waxy residue or foreign material.
SMA412B
Tool number
: EG17650301 (J-33984-A)
Testing pressure
: 137 kPa (1.4 kg/cm
2
, 20 psi)
WBIA0568E
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ENGINE COOLANT
2.
Pull the negative-pressure valve to open it and check that it
closes completely when released.
• Check that there is no dirt or damage on the valve seat of the
reservoir cap negative-pressure valve.
• Check that there are no abnormalities in the opening and clos-
ing conditions of the negative-pressure valve.
3.
Check reservoir cap relief pressure using suitable tool and Tool.
NOTE:
• Apply engine coolant to the cap seal surface.
• Replace the reservoir cap if there is any damage in the nega-
tive-pressure valve, or if the open-valve pressure is outside of
the limit.
CHECKING RADIATOR CAP
Inspect the radiator cap.
NOTE:
Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.
• Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.
• Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the
metal retainer.
CHECKING RADIATOR
Check radiator for mud or clogging. If necessary, clean radiator as follows.
CAUTION:
• Be careful not to bend or damage the radiator fins.
• When radiator is cleaned without removal, remove all surrounding parts such as cooling fan shroud
and horns. Then tape the harness and electrical connectors to prevent water from entering.
1.
Apply water by hose to the back side of the radiator core, with the hose pointed vertically downward.
2.
Apply water again to all radiator core surfaces once per minute.
3.
Stop washing if any stains no longer flow out from the radiator.
4.
Blow air into the back side of radiator core, with the air hose pointed vertically downward.
• Use compressed air lower than 490 kPa (5 kg/cm
2
, 71 psi) and keep distance more than 30 cm (11.8 in).
5.
Blow air again into all the radiator core surfaces once per minute until no water sprays out.
6.
Check for leaks.
Changing Engine Coolant
INFOID:0000000005276084
WARNING:
• To avoid being scalded, never change the coolant when the engine is hot.
• Wrap a thick cloth around the cap to carefully remove the cap. First, turn the cap a quarter of a turn
to release any built-up pressure, then push down and turn the cap all the way to remove it.
DRAINING ENGINE COOLANT
1.
Turn ignition switch ON and set temperature control lever all the way to HOT position or the highest tem-
perature position. Wait 10 seconds and turn ignition switch OFF.
2.
Remove the engine front under cover. Refer to
EXT-13, "Removal and Installation"
.
SMA967B
Tool number
: EG17650301 (J-33984-A)
Standard: 98 – 118 kPa (1.0 – 1.2 kg/cm
2
, 14 – 17 psi)
WBIA0570E
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