Contents Section: Cooling System (Mechanical) All sections

Engine Cooling System (MR20DE): Diagnosis Nissan Sentra B16 рестайлинг

Cooling System (Mechanical) 9 illustrations ~330 words

Troubleshooting Chart

SymptomCheck items
Cooling system parts malfunctionPoor heat transferWater pump malfunctionWorn or loose drive belt
Thermostat stuck closedThermostat
Damaged finsDust contamination or paper clogging
Physical damage
Clogged radiator cooling tubeExcess foreign material (rust, dirt, sand, etc.)
Reduced air flowCooling fan does not operateEngine cooling fans
High resistance to fan rotation
Damaged fan blades
Damaged radiator shroudRadiator shroud
Improper engine coolant mixture ratioEngine coolant viscosity
Poor engine coolant qualityPeriodic maintenance
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pumpPoor sealing
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
Power train system malfunction
Installed improper size wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air flowBlocked bumperInstalled front bumper fascia cover
Blocked radiator grilleMud contamination or paper clogging
Blocked radiatorBlocked air flow
Blocked condenser
Installed large fog lamp

TROUBLESHOOTING CHART

Scheme 5

Scheme 5: Cooling Circuit

Scheme 6

Scheme 6

Inspection

WARNINGNever remove the radiator cap when the engine is hot. Serious burns could occur from high pressure fluid escaping from the radiator. Wrap a thick cloth around the cap. Slowly push down and turn it a quarter turn to allow built-up pressure to escape. Carefully remove the cap by pushing down and turning it all the way.

INSPECTION AFTER REMOVAL

Inspect radiator for leaks as follows

Scheme 7

Scheme 7: INSPECTION AFTER REMOVAL

Scheme 8

Scheme 8
  1. Apply pressure using suitable tool and Tool. Specified pressure value : 157 kPa (1.6 kg/cm 2 , 23 psi) Tool number : EG17650301 (J-33984-A) WARNING: To prevent the risk of the hose coming undone while under pressure, securely fasten it down with a hose clamp.
  2. Check for leakage.

INSPECTION AFTER INSTALLATION

  1. Check for leaks of engine coolant. Refer to " INSPECTION ".
  2. Start and warm up engine. Visually check if there is no leaks of engine coolant and CVT fluid if equipped. Refer to CVT FLUID .

Scheme 9

Scheme 9: Component
  1. Check for leaks of engine coolant. Refer to " INSPECTION ".
  2. Start and warm up the engine. Visually check for leaks of engine coolant.

Scheme 10

Scheme 10: Component

Scheme 11

Scheme 11
  1. Check for leaks of engine coolant. Refer to " INSPECTION ".
  2. Start and warm up the engine. Visually check for engine coolant leaks.

Scheme 12

Scheme 12: Component

Scheme 13

Scheme 13
  1. Place a thread (A) so that it is caught in the valve of the water control valve (1). Immerse fully in a container (B) filled with water. Heat while stirring.
  2. The valve opening temperature is the temperature at which the water control valve opens and falls from the thread.
  3. Continue heating. Check the full-open valve lift amount. NOTE: The full-open valve lift amount standard temperature for the water control valve is the reference value.
  4. After checking the full-open valve lift amount, lower the water temperature and check the valve closing temperature. WATER CONTROL VALVE SPECIFICATION Items Water control valve Valve opening temperature 93.5 - 96.5°C (200 - 206°F) Full-open valve lift amount More than 8 mm/108°C (0.315 in/226°F) Valve closing temperature 90°C (194°F)
  5. If out of the specification, replace water control valve.
  1. Check for leaks of engine coolant. Refer to " INSPECTION ".
  2. Start and warm up the engine. Visually check if there is no leaks of engine coolant.