Engine Cooling System: Maintenance Infiniti Q45 III

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

Scheme 15

Scheme 16

1. Drain engine coolant from the radiator. Refer to " «CHANGING ENGINE COOLANT»(ref-183866-S19457821222005081700000) ". CAUTION: Perform when the engine is cold.
2. Remove cooling fan shroud. Refer to " «COOLING FAN»(ref-183866-S08949419212005081700000) ".
3. Remove A/T oil cooler hoses. Install blind plug to avoid leakage of A/T fluid.
4. Remove bolts of both right/left end of radiator core (2 bolts for each).
5. Lift the air conditioner condenser up approximately 2 cm (0.79 in). Remove the clips from the right and left flange parts of the air conditioner condenser. CAUTION: To avoid putting a load on the air conditioner piping, be careful not to lift too much.
6. Lift up and remove the radiator. CAUTION: Do not damage or scratch radiator core when removing. After removing the radiator, fix the air conditioner condenser on the vehicle side with a rope or similar means. This is to prevent a load being applied to the air conditioner piping.

Attaching The Fluid Pipe Fixing Clip

If the fluid pipe fixing clip has been removed from the installation holes, it must be replaced with a new clip.

Adding Cooling Fan Fluid And Bleeding Air

The procedure below is for adding cooling fan fluid and bleeding air from the piping.

Note. The total fluid volume is 777 ml (26.3 US fl oz, 27.4 Imp fl oz) (with the cold maximum on the level gauge when the engine is cold). Add fluid to the reservoir tank until the fluid reaches the upper limit of the "HOT" level on the level gauge. For the fluid level, refer to " INSPECTION AFTER INSTALLATION ". Start the engine. Run the engine at idle speed for a few minutes. Then check the fluid level. If the level has decreased, add fluid. CAUTION: Be careful not to touch the fan while it is rotating. Be sure to add fluid as necessary. If the fluid runs out in the reservoir tank, air will be taken in. NOTE: With the engine operating, the reservoir tank cap can be removed to check the fluid level. Immediately after starting, certain noise will come from the fluid pump. This is caused by air taken in to the piping and will gradually disappear. Continue with step 3 until the level of the fluid stops decreasing. Stop the engine and disconnect the harness connector for the cooling fan speed control solenoid valve. NOTE: When the solenoid valve harness is disconnected, the fan will operate at full speed. Start the engine. Repeat step 3 until the fluid level stops decreasing and air bubbles stop coming out. Stop the engine. Connect the harness connector for the cooling fan speed control solenoid valve.

Scheme 17

1. Check that there is no fluid leakage from any hose connection or any other part.
2. Check the fluid level with the level gauge on the reservoir tank cap. If there is too much or too little, adjust the amount of fluid.
3. Check that under the fluid temperature conditions below, the fluid level is within the "COLD" or "HOT" range on the level gauge. COLD : Fluid temperature 0 - 30 °C (32 - 86 °F) HOT : Fluid temperature 50 - 80 °C (122 - 176 °F) NOTE: There is no specified timing for replacing the fluid. Refer to "DTC P1480 COOLING FAN SPEED CONTROL SOLENOID VALVE " for control of cooling fan.

Scheme 18

Scheme 19

1. Remove fan. CAUTION: Reverse screws are used for the fan attachment nuts. When removing or attaching, turn the nut the opposite way as for a normal screw. Do not remove the balancer clip from the fan. For the case if the balancer clip is removed, make an alignment mark for the installation position on the fan side.
2. Remove cooling fan motor from cooling fan shroud.