| Symptom | Check items | |||
|---|---|---|---|---|
| Cooling system parts malfunction | Poor heat transfer | Water pump malfunction | Worn or loose drive belt | Engine coolant circulation |
| Thermostat stuck closed | Thermostat | |||
| Damaged radiator fins | Dust contamination or paper clogging | — | ||
| Physical damage | ||||
| Clogged radiator cooling tube | Excess foreign material (rust, dirt, sand, etc.) | |||
| Reduced air flow | Cooling fan does not operate | Cooling fan assembly | — | |
| 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 | — | Engine coolant density | — | |
| Insufficient engine coolant | Engine coolant leaks | Radiator and heater hoses | 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 | — | |||
| Improper size wheels and tires installed | ||||
| Brakes dragging | ||||
| Improper ignition timing | ||||
| — | Blocked or restricted air flow | Blocked bumper | — | |
| Blocked condenser | ||||
| Blocked radiator | ||||
| Blocked radiator grille | ||||
| Car brassiere installed | ||||
| Large fog lamp installed | ||||
| Mud contamination or paper clogging | ||||

| 1. | Cylinder block (bank 1) | 2. | Oil cooler | 3. | Cylinder head (RH) |
| 4. | Water pump | 5. | Radiator | 6. | Water outlet |
| 7. | Thermostat | 8. | Cylinder head (LH) | 9. | Cylinder block (bank 2) |
| A. | To heater core. Refer to Exploded View. | B. | To A/T fluid warmer. Refer to Exploded View. | C. | From heater core. Refer to Exploded View. |
| D. | From A/T fluid warmer. Refer to Exploded View. |

| 1. | Radiator | 2. | Reservoir tank | 3. | Thermostat assembly (water inlet) |
| 4. | Water connector | 5. | Water pump | 6. | Cylinder block |
| 7. | Cylinder block | 8. | Water outlet | 9. | Oil cooler |
| 10. | Heater core | 11. | A/T fluid warmer | A. | Thermostat closed |
| B. | Thermostat open |
Nissan Pathfinder Info Center
Email: info@nipathfinder.com
Phone: +1 (800) 123-4567
Address: 123 Pathfinder Blvd, Nashville, TN 37214, USA
Working Hours: Mon–Fri, 9:00 AM – 5:00 PM (EST)