Nissan Sentra Service Manual: Symptom diagnosis
OVERHEATING CAUSE ANALYSIS
Troubleshooting Chart
| Symptom | Check items | |||
| Cooling system parts malfunction | Poor heat transfer | Water pump malfunction | Worn or loose drive belt | — |
| Thermostat stuck closed | Engine coolant circulation | |||
| Damaged fins | Dust contamination or rock clogging | |||
| Mechanical damage | ||||
| Clogged radiator cooling tube | Excess foreign material (rust, dirt, sand, etc.) | |||
| Reduced air flow | Cooling fan does not operate | Fan shroud and motor as- High resistance to fan rota- sembly | — | |
| High resistance to fan rotation | ||||
| Damaged fan blades | ||||
| Damaged radiator shroud | — | Radiator shroud | — | |
| Improper engine coolant mixture ratio | — | Engine coolant viscosity | — | |
| Poor engine coolant quality | — | Periodic maintenance | — | |
| 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, deterioration or improper fitting | |||
| Cracked radiator tank | ||||
| Cracked radiator core | ||||
| Reservoir tank | Cracked reservoir tank | |||
| Overflowing reservoir tank | Exhaust gas leaks into cooling system | Cylinder head deterioration | ||
| Cylinder head gasket deterioration | ||||
| Except cooling system parts malfunction |
— |
Overload on engine | Abusive driving | High 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 flow | Blocked radiator grille | Installed car brassiere | — | |
| Blocked bumper | ||||
| Blocked radiator | ||||
| Blocked condenser | Mud contamination or paper clogging | |||
| Installed large fog lamp | ||||
System description
DESCRIPTION
Engine Cooling System Schematic
CVT Models
Radiator
Water inlet
Reservoir tank
Thermostat
Engine oil cooler
Thermostat housing
Water pump
Cylinder head
Cylinder b ...
Periodic maintenance
ENGINE COOLANT
System Inspection
WARNING:
Do not remove the radiator cap when the engine is hot. Serious
burns could occur from high pressure
engine coolant escaping from the radiator.
Wr ...
Other materials:
Basic inspection
Diagnosis and repair work flow
Work flow
OVERALL SEQUENCE
DETAILED FLOW
1.INTERVIEW FOR MALFUNCTION
Find out what the customer's concerns are.
>> GO TO 2
2.SYMPTOM CHECK
Verify the symptom from the customer's information.
>> GO TO 3
3.BASIC INSPECTION
Check the operation ...
Heating and cooling unit assembly
Exploded view
With air conditioning
Defroster seal
Center ventilator seal
Upper distribution module
Side ventilator seal (LH)
Blower motor
Blower unit
Intake door motor
Power transistor
Power transistor wiring harness
Front floor duct (lh)
Vent and defroster linkage
Mo ...
Precaution for Work
When removing or disassembling each component, be careful not to damage
or deform it. If a component
may be subject to interference, be sure to protect it with a shop cloth.
When removing (disengaging) components with a screwdriver or similar
tool, be sure to wrap the component
with a ...
