Late Model Infiniti Coolant Flushing Procedure

[SteveTheTech]

In this article I will highlight the proper procedure for flushing and filling the coolant in your G35, M34,M45,I30,I35,FX35,FX45 and QX4. This procedure is slightly different on the QX56 and if anyone has questions feel free to email me and I can explain it to you.

Replacing the coolant is a vital step in the keeping your Infiniti running properly for many to come. With a good high quality ethylene glycol mixture, you will have a clean coolant circuit and consistent operating temperature. I prefer the factory coolant, it is a bit pricey but with something that is that important and doesn't require frequent replacement the piece of mind is worth it.

Skill Level 3 of 5

Time Required usually <1hr

Tools Required

-#2 Phillips Screwdriver- Ideally two (one stubby for the radiator drain, and one 12in+ for the bleeder plug)

-1-2 Gallons of High Quality Ethelyn Glycol (I recommend Nissan P/N 999MP-AF000P)

-Radiator Funnel or Airlift type Vacuum Refill Tool

REFILLING ENGINE COOLANT

1. Install reservoir tank, and radiator drain plug.CAUTION:Be sure to clean drain plug and install with new O-ring.If cylinder block drain plugs are removed, close and tighten them.

2. Remove air relief plug on heater hose.



3. Fill radiator and reservoir tank to specified level.Pour engine coolant through engine coolant filler neckslowly of less than 2 (2-1/8 US qt, 1-3/4 lmp qt) a minuteto allow air in system to escape.

Use Genuine Nissan Long Life Antifreeze/ Coolant orequivalent mixed with water (distilled or demineralized).

Refer to the GI section, "RECOMMENDED CHEMICAL PRODUCTSAND SEALANTS" .When engine coolant overflows air relief hole on heater hose,install air relief plug with new O-ring.

4. Warm up engine to normal operating temperature with radiator cap installed.

5. Run engine at 3,000 rpm for 10 seconds and return to idle speed.Repeat two or three times.

CAUTION:Watch water temperature gauge so as not to overheat engine.

6. Stop engine and cool down to less than approximately 50°C (122°F).Cool down using a fan to reduce the time.If necessary, refill radiator up to filler neck with engine coolant.

Radiator drain plug:: 0.78 - 1.6 N·m (0.08 - 0.16 kg-m, 7 - 14 in-lb)

Engine coolant capacity (Approximate)(with reservoir tank at “MAX” level): 8.5 (9 US qt, 7-1/2 lmp qt) for A/T models: 8.7 (9-1/4 US qt, 7-5/8 lmp qt) for M/T models

Reservoir tank capacity (at “MAX” level): 0.8 (7/8 US qt, 3/4 lmp qt)Air relief plug:: 0.78 - 1.6 N·m (0.08 - 0.16 kg-m, 7 - 14 in-lb)

ENGINE COOLANT

7. Refill reservoir tank to “MAX” level line with engine coolant.

8. Repeat steps 3 through 6 two or more times with radiator cap installed until engine coolant level no longerdrops.

9. Check cooling system for leaks with engine running.

10. Warm up engine, and check for sound of engine coolant flow while running engine from idle up to 3,000rpm with heater temperature controller set at several position between “COOL” and “WARM”.

Sound may be noticeable at heater unit.

11. Repeat step 10 three times.

12. If sound is heard, bleed air from cooling system by repeating step 3 through 6 until engine coolant level nolonger drops.

Clean excess engine coolant from engine.

FLUSHING COOLING SYSTEM

1. Fill radiator with water until water spills from the air relief hole, then close air relief plug.

Fill radiator and reservoir tank with water and reinstall radiator cap.

2. Run engine and warm it up to normal operating temperature.

3. Rev engine two or three times under no-load.

4. Stop engine and wait until it cools down.

5. Drain water from the system.

6. Repeat steps 1 through 5 until clear water begins to drain from radiator.

If you have access to a vacuum refilling tool I would highly recommend using that to pull a vacuum on the system. This will alleviate the need to rev the engine to get heat at idle and a stable coolant temperature. I prefer to mix my coolant and water in a large container and put the suction hose into it to ensure the correct mixture of 50% Long Life Antifreeze and (ideally)50% distilled water.

All modern Nissan engines are very picky about the coolant ratio and skipping the 50/50 mixture will cause heating and cooling capabilities. Also replacing the radiator cap is always a good call when the the underside rubber seals show indentation. (Note: I will try to find a picture of this and add it this page)