Engine Cooling System: Maintenance Infiniti QX56 II

Draining

Scheme 17

1. Open radiator drain plug (1) at the bottom of radiator, and then remove radiator cap and reservoir tank cap. When draining all of engine coolant in the system, open water drain plug on cylinder block. Refer to " «SETTING»(ref-390336-S39804481782011032600000) ".
2. Remove reservoir tank if necessary, and drain engine coolant and clean reservoir tank before installing.
3. Check drained engine coolant for contaminants such as rust, corrosion or discoloration. If contaminated, flush the engine cooling system. Refer to " «FLUSHING»(ref-390338-S41618702202011032600000) ".

Scheme 18

Scheme 19

Scheme 20

1. Install reservoir tank if removed, and radiator drain plug. CAUTION: Be sure to clean drain plug and install with new O-ring. Refer to " «EXPLODED VIEW»(ref-390338-S33393789322011032600000) ". : 1.96 N.m (0.2 kg-m, 17 in-lb) If water drain plug on cylinder block is removed, close and tighten it. Refer to " «DISASSEMBLY AND ASSEMBLY»(ref-390336-S22065270662011032600000) ".
2. Check that each hose clamp is firmly tightened.
3. Remove air relief plug (1) on heater hose.
4. Fill radiator, and reservoir tank, to specified level. Pour engine coolant through engine coolant filler neck slowly of less than 3 l (2-5/8 lmp qt) a minute to allow air in system to escape. Use Genuine NISSAN Long Life Antifreeze/Coolant or equivalent mixed with water (distilled or demineralized). Refer to " «FLUIDS AND LUBRICANTS»(ref-390339-S33039736222011032600000) ". Engine coolant capacity : Refer to " «PERIODICAL MAINTENANCE SPECIFICATION»(ref-390338-S15816721872011032600000) ". (With reservoir tank at "MAX" level) Reservoir tank engine coolant capacity :Refer to " «PERIODICAL MAINTENANCE SPECIFICATION»(ref-390338-S15816721872011032600000) ". (At "MAX" level)
5. When engine coolant overflows air relief hole on heater hose, install air relief plug with clamp. Then refill radiator with engine coolant.
6. Install radiator cap.
7. Install reservoir tank cap.
8. Warm up engine until opening thermostat less than 3,000 rpm. Check thermostat opening condition by touching radiator hose (lower) to see a flow of warm water. CAUTION: Watch water temperature gauge so as not to overheat engine.
9. Stop the engine and cool down to less than approximately 50°C (122°F). Cool down using fan to reduce the time. If necessary, refill radiator up to filler neck with engine coolant.
10. Refill reservoir tank to "MAX" level line with engine coolant if necessary.
11. Repeat steps 6 through 10 two or more times with reservoir tank cap installed until engine coolant level no longer drops.
12. Check cooling system for leakage with engine running.
13. Warm up the engine, and check for sound of engine coolant flow while running engine from idle up to 3,000 rpm with heater temperature controller set at several position between "COOL" and "WARM". Sound may be noticeable at heater unit.
14. Repeat step 13 three times.
15. If sound is heard, bleed air from cooling system by repeating step 4 , and steps from 6 to 14 until engine coolant level no longer drops.

Scheme 21

1. Install reservoir tank if removed, and radiator drain plug. CAUTION: Be sure to clean drain plug and install with new O-ring. Refer to " «EXPLODED VIEW»(ref-390338-S33393789322011032600000) ". : 1.96 N.m (0.2 kg-m, 17 in-lb) If water drain plug on cylinder block is removed, close and tighten it. Refer to " «DISASSEMBLY AND ASSEMBLY»(ref-390336-S22065270662011032600000) ".
2. Remove air relief plug (1) on heater hose.
3. Fill radiator and reservoir tank with water until water spills from the air relief holes, then close air relief plugs with clamp. Fill radiator and reservoir tank with water and reinstall caps.
4. Run the engine and warm it up to normal operating temperature.
5. Rev the engine two or three times under no-load.
6. Stop the engine and wait until it cools down.
7. Drain water from the system. Refer to " «DRAINING»(ref-390338-S32619258492011032600000) ".
8. Repeat steps 1 through 7 until clear water begins to drain from radiator.

Scheme 22

Scheme 23

Scheme 24

1. Check valve seat of reservoir tank cap. Check if valve seat (A) is swollen to the extent that the edge of the metal plunger (B) cannot be seen when watching it vertically from the top. Check if valve seat has no soil and damage.
2. Pull negative-pressure valve to open it, and check that it close completely when released. Check that there is no dirt or damage on the valve seat of reservoir tank cap negative-pressure valve. Check that there are no unusualness in the opening and closing conditions of negative-pressure valve.
3. Check reservoir tank cap relief pressure. When connecting reservoir tank cap to the radiator cap tester (commercial service tool) and the radiator cap tester adapter (commercial service tool) (A), apply engine coolant to the cap seal surface. Standard and limit : Refer to " «RADIATOR»(ref-390338-S23173008412011032600000) ".
4. Replace reservoir tank cap if there is an unusualness related to the above three.