Community Member Credit: Frank / motorvate.ca

Changing your coolant on a regular basis is very important to the longevity of your engine. With normal use, the corrosion inhibitors loose their effectiveness. Nissan recommends that AFTER the first 96,000 KM replace the coolant every 24 months, or 48,000 KM. The procedure that I am following is detailed in the Nissan Maxima’s Owners Manual, in the “Do it Yourself section.”

The engine must be COLD! Do not try this on a WARM or HOT engine. You may warp the block or the heads!

First we must open the valve in the heater core, to allow the coolant to drain out of it. There are two way to do this, depending on the type of climate control you have.

Manual Climate Control
Turn the ignition key to “ON” (one position before “START”), and put you heater control to the maximum hot position. Turn the ignition key back to “OFF”

Automatic Climate Control
If you have the Automatic Climate option (as shown below) you need to do the following to open the valve in heater core:

Turn the ignition switch from the “OFF” to the “ON” position

With in 5 seconds of being switched “ON” push the “OFF” button on the climate control for at least 5 seconds.

Press the “HOT” button 3 times

Press the “DEFROST” button 2 times. Code 43 will be displayed.

Wait 10 seconds before switching the ignition to “OFF”

I like to use a pan like the one shown to catch the coolant. You can use a pail, but then you may have to jack up the car in order to get the pail to fit under the car.

This is the PLASTIC drain plug that is in the bottom of the radiator. Use a large Phillips screw driver to remove it.

Coolant draining from the radiator into the container.

Remove the radiator cap.

Remove the clip on the radiator, and pull off the hose. This hose goes to the reservoir tank. Right:

Here is an inside view of my reservoir tank. It is very dirty, and needs removed to be cleaned. Once the hose is removed from the rad, the reservoir bottle can be pulled out of it’s bracket. Flush out the reservoir with a hose, and maybe a small brush to get it clean. Reinstall the coolant reservoir, hose and clamp.

INSET Photo: Cleaned reservoir bottle.

Front coolant plug. This is used to drain the coolant from the front bank of cylinders.

Rear coolant plug. This is used to drain the coolant from the front bank of cylinders. Your owners manual has a nice picture to show you their location.

These plugs are VERY difficult to access! If you remove the Y-pipe (factory or aftermarket) you will have more room. Remove the plugs, let the coolant drain. Use thread sealer on the threads, and tighten to 13-15 foot-lbs

-OR-

Don’t remove these plugs. At most the engine may contain about 2 liters of coolant. When I added coolant the rad took 5 liters (total engine engine/rad capacity is 7 liters, plus 2 liters for the reservoir). Most of the coolant is being changed (5 out of 7 liters), and from now on, I will change my coolant using this method every year.

What ever you decide to do, you should flush the rad with water. This will remove any sediment and the old coolant. To do this, simply put the water hose in the filler neck of the rad, let water flow thru the rad, and exit the bottom. Make sure that you capture all the coolant in a container, for recycling.

Install the rad drain plug. Make sure the rubber washer is in place. (indicated by arrow)

Check the rad cap for any tears in the rubber. Using a clean rag, wipe off any foreign matter on the rubber seal. Gently lift up the metal “hat” as shown by the arrow, and wipe off the “hat” and rubber under the “hat” This is the valve the allows coolant to enter the rad, from the reservoir bottle as the car cools.

Make life easy for yourself. Pre mix a 50/50 mixture of coolant and soft water. This will protect you from -37°C to 129°C.

Pour in the 50/50 mixture S-L-O-W-L-Y. This will allow time for air to escape.

Install the radiator cap.

Start the engine, and let the car warm up, until it reaches operating temperature.

Race the engine 2 or 3 times in neutral. Keep an eye on the coolant temperature, just incase the motor starts to overheat.

Let the engine completely cool down.

Top off the rad to the bottom of the hole for the reservoir hose.

Fill reservoir to the “H” mark with mixture of 50/50 coolant and soft water.

Check the rad drain plug for any signs of leaking

Recycle the old coolant

After a few days, with the engine cool, check for leaks, check the coolant level, and check the freezing / boiling point to ensure it meets your requirements. For most of Canada, a 50/50 mix should protect you. (down to –37°C)

Do not leave the old coolant in an uncovered container.

Animals like the smell and taste (very sweet) but it will KILL THEM.  Recycle it as soon as possible!