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:
P0139 HO2S2
DTC Logic
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxygen
storage capacity of the three way catalyst 1 causes the longer
switching time. To judge the malfunctions of heated oxygen sensor
2, ...
Maintenance precautions
When performing any inspection or maintenance
work on your vehicle, always take care to prevent
serious accidental injury to yourself or damage to
the vehicle. The following are general precautions
which should be closely observed.
WARNING
Park the vehicle on a level surface, apply
...
Steering wheel switch for audio control (if so equipped)
Tuning switch
Power on and SOURCE select switch
Volume control button
The audio system can be operated using the
controls on the steering wheel.
POWER on switch
With the ignition switch in the ACC or ON position,
push the SOURCE switch to turn the audio
system on.
SOURCE select s ...
