Contents Wiring diagrams Section: Cooling Fan All sections

Engine Cooling System: Diagnosis Nissan Quest III

Cooling Fan 7 illustrations ~313 words

Troubleshooting Chart

SymptomCheck items
Cooling system parts malfunctionPoor heat transferWater pump malfunctionWorn or loose drive belt
Thermostat stuck closedCoolant circulation
Damaged finsDust contamination or paper clogging
Physical damage
Clogged radiator cooling tubeExcess foreign material (rust, dirt, sand, etc.)
Reduced air flowCooling fan does not operateFan assembly
High resistance to fan rotation
Damaged fan blades
Damaged radiator shroudRadiator shroud
Improper coolant mixture ratioCoolant viscosity
Poor coolant quality
Insufficient coolantCoolant leaksCooling hoseLoose clamp Cracked hose Poor sealing
Heater pump
Water pump
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterioration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tankCracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into cooling systemCylinder head deterioration
Cylinder head gasket deterioration
Except cooling system parts malfunctionOverload on engineAbusive drivingHigh engine rpm under no load
Driving in low gear for extended time
Driving at extremely high speed
Powertrain system malfunction
Installed improper size wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air flowBlocked radiator grilleInstalled car brassiere
Blocked bumperMud contamination or paper clogging
Blocked radiator
Blocked condenser

OVERHEATING CAUSE ANALYSIS TROUBLESHOOTING CHART

Scheme 1

Scheme 1: Cooling Circuit

Scheme 2

Scheme 2: System Drawing

INSPECTION AFTER INSTALLATION

  1. Check for engine coolant leaks. Refer to , " «CHECKING COOLING SYSTEM FOR LEAKS»(ref-239944-S05600405852006080400000) ".
  2. Start and warm up the engine. Visually make sure that there are no engine coolant leaks or A/T fluid leaks.
  1. Check for engine coolant leaks. Refer to , " «CHECKING COOLING SYSTEM FOR LEAKS»(ref-239944-S05600405852006080400000) ".
  2. Start and warm up engine. Visually inspect that there are no engine coolant or A/T fluid leaks.

Scheme 3

Scheme 3: Disassembly and Assembly of Radiator Fan
  1. Check for engine coolant leaks. Refer to , " «CHECKING COOLING SYSTEM FOR LEAKS»(ref-239944-S05600405852006080400000) ".
  2. Start and warm up the engine. Visually make sure that there are no engine coolant leaks or A/T fluid leaks.

Scheme 4

Scheme 4: Removal and Installation

Scheme 5

Scheme 5: REMOVAL
  1. Drain coolant. Refer to , " «CHANGING ENGINE COOLANT»(ref-239944-S24399931942006080400000) ". CAUTION: Perform when engine is cool.
  2. Remove IPDM E/R bolts and position aside. Refer to , " «REMOVAL AND INSTALLATION OF IPDM E/R»(ref-239939-S09181280512006080300000) ".
  3. Disconnect lower radiator hose.
  4. Disconnect oil cooler line.
  5. Remove engine coolant inlet and thermostat assembly. Do not disassemble engine coolant inlet and thermostat assembly. Replace them as a unit, if necessary.

Scheme 6

Scheme 6: INSPECTION AFTER REMOVAL
  1. Check valve seating condition at ordinary room temperatures. It should seat tightly.
  2. Check valve opening temperature and maximum valve lift. THERMOSTAT VALVE TEMPERATURE Thermostat Standard Values Valve opening temperature 80 - 84°C (176 - 183°F) Valve lift 8.6 mm/95°C (0.339 in/203°F) Valve closing temperature 77°C (171°F) or lower
  1. Check for engine coolant leaks. Refer to , " «CHECKING COOLING SYSTEM FOR LEAKS»(ref-239944-S05600405852006080400000) ".
  2. Start and warm up the engine. Visually make sure that there are no engine coolant leaks or A/T fluid leaks.

Scheme 7

Scheme 7: Removal and Installation
  1. Check for engine coolant leaks. Refer to , " «CHECKING COOLING SYSTEM FOR LEAKS»(ref-239944-S05600405852006080400000) ".
  2. Start and warm up the engine. Visually make sure that there are no engine coolant leaks or A/T fluid leaks.