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Engine Cooling System: Diagnosis Infiniti EX35 I

Cooling System (Mechanical) 6 illustrations ~581 words

Troubleshooting Chart

SymptomCheck items
Cooling system parts malfunctionPoor heat transferWater pump malfunctionWorn or loose drive belt
Thermostat stuck closed
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 shroud
Improper engine coolant mixture ratio
Poor engine coolant qualityEngine coolant density
Insufficient engine coolantEngine coolant leakageCooling 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 leakage 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 bumper
Blocked radiator grilleInstalled car brassiere
Mud contamination or paper clogging
Blocked radiator
Blocked condenserBlocked air flow
Installed large fog lamp

TROUBLESHOOTING CHART

RADIATOR : Inspection

Check radiator for mud or clogging. If necessary, clean radiator as follows

  1. Be careful not to bend or damage radiator fins.
  2. When radiator is cleaned without removal, remove all surrounding parts such as radiator cooling fan assembly and horns. Then tape harness and connectors to prevent water from entering.
  1. Apply water by hose to the back side of the radiator core 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 radiator.
  4. Blow air into the back side of radiator core 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.

Scheme 3

Scheme 3: Exploded View
Scheme 3: Exploded View

Refer to " Components " for symbols in the figure.

INSPECTION AFTER INSTALLATION

  1. Check for leakage of engine coolant using the radiator cap tester adapter (commercial service tool) and the radiator cap tester (commercial service tool). Refer to " «INSPECTION»(ref-368795-S08933888772010081300000) ".
  2. Start and warm up the engine. Visually check that there is no leakage of engine coolant and A/T fluid.

Scheme 4

Scheme 4: Exploded View
Scheme 4: Exploded View

Refer to " Components " for symbols not described on the above.

INSPECTION AFTER REMOVAL

Check that fan motors operate normally.

Note. Cooling fans are controlled by cooling fan control module. For details, refer to " Component Parts Location ".

INSPECTION AFTER DISASSEMBLY

Cooling Fan

Inspect cooling fan for crack or unusual bend.

  1. If anything is found, replace cooling fan.

Scheme 5

Scheme 5: Exploded View
Scheme 5: Exploded View

Refer to " Components " for symbols in the figure.

  1. Check that the reservoir tank cap is tightened.
  2. Check for leakage of engine coolant using the radiator cap tester adapter (commercial service tool) and the radiator cap tester (commercial service tool). Refer to " «INSPECTION»(ref-368795-S08933888772010081300000) ".
  3. Start and warm up the engine. Visually check that there is no leakage of engine coolant.

Scheme 6

Scheme 6: Exploded View
Scheme 6: Exploded View

Refer to " Components " for symbols in the figure.

Scheme 7

Scheme 7: REMOVAL
Scheme 7: REMOVAL
  1. Remove engine cover. Refer to " «Exploded View»(ref-368797-S08623518782010081300000) ".
  2. Remove air duct and air cleaner case assembly (LH). Refer to " «Exploded View»(ref-368797-S19785767342010081300000) ".
  3. Remove reservoir tank. Refer to " «EXPLODED VIEW»(ref-368795-S35101085722010081300000) ".
  4. Remove engine undercover with power tool.
  5. Drain engine coolant from radiator drain plug at the bottom of radiator. Refer to " «DRAINING»(ref-368795-S05263292432010081300000) ". CAUTION: Perform this step when the engine is cold. Never spill engine coolant on drive belt.
  6. Disconnect radiator hose (lower).
  7. Disconnect intake valve timing control solenoid valve harness connector (bank 2), and remove intake valve timing control solenoid valve.
  8. Remove water inlet and thermostat assembly (1). CAUTION: Never disassemble water inlet and thermostat assembly. Replace them as a unit, if necessary.
  1. Check that the reservoir tank cap is tightened.
  2. Check for leakage of engine coolant using the radiator cap tester adapter (commercial service tool) and the radiator cap tester (commercial service tool). Refer to " «INSPECTION»(ref-368795-S08933888772010081300000) ".
  3. Start and warm up the engine. Visually check that there is no leakage of engine coolant.

Scheme 8

Scheme 8: Exploded View
Scheme 8: Exploded View

Refer to " Components " for symbols in the figure.

  1. Check that the reservoir tank cap is tightened.
  2. Check for leakage of engine coolant using the radiator cap tester adapter (commercial service tool) and the radiator cap tester (commercial service tool). Refer to " «INSPECTION»(ref-368795-S08933888772010081300000) ".
  3. Start and warm up the engine. Visually check that there is no leakage of engine coolant.

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