As it got colder and I was using the Heat, I found that it was not ‘Hot’ at Idle and following shutting the Engine I was able to hear the Air Bubbles traveling through the Heater Core. As this is a commonly discussed issue, I knew that it was an issue with Air in the Cooling System. With a bunch of reading, I decided the best method was the one that ‘rckev’ used. His method was to connect a Hose to the T-fitting on the Firewall. This is how I did mine.

The first time I did it, I just topped off the Reservoir to the Full Line and then connected the Hose. The first time didn’t work, because I think I ended up putting more Air in some how? I don’t know.

First step is to pick up the Coolant from your Nissan Dealership. Don’t be cheap or lazy and buy one that says ‘use with any color’ or ‘mixes with green’. It's not formulated the same. End of story. If you did use something else there is nothing I can say. I don’t know what will happen. Start you own thread and title it “Is This Bad?” or whatever you want. Maybe even search first.

Here is the Nissan Coolant:


Say thank you to the Parts Dept Guy and swing by the Drugstore or Auto Parts Store on the way home. Pick up a Gallon of Distilled Water to mix the Coolant. This makes your One Gallon of Coolant into 50/50 mixed Two Gallons! About the same price as the premixed crap at the Auto Parts Store and correctly formulated.


Stop by Home Depot or similar and pick up some Clear Plastic Tubing. I got a section of 5/16” Outer Diameter and 3/16” Inner Diameter Tube, but it was a little tight. You can also use 5/16” ID.


OK, now its time to mix. I used a One-liter Seltzer Bottle and filled it Half and Half. If you have a clean 2-gallon Container that is re-sealable that would be ideal. You need something that would screw shut. A word of advise. Don’t use something that had anything in it, but water previously and wash out the container. You don’t want random chemicals and sediment in your Engine.


Cut a section of Tube about 33” in length.


Now we are ready to put on a coat and get to work. With the Engine Cold, open up the Radiator Cap and fill it to the top, then recap. I added a lot here, a little under a Liter. This is where I eat my words a bit. I thought that RIXterra had an issue when he used a Liter, but I ended up using 1.6!


Once the Radiator is full, locate the T-fitting on the Passenger-side Firewall. It’s circled here; you can see the spilled Coolant dried up from last time.


You need a pair of Pliers to remove the Clamp, once removed the Rubber Cap should slide up an off. I wasn’t worried about the Air getting in at this point or Coolant leaking out. Like I said before, the Tube was a little tight so I supported the fitting from underneath while pushing the Tube on from the top.

Run the Tube over to the Overflow Reservoir and top up the Reservoir to the Full Line. Make sure the end of the Hose is submerged in the Coolant. You don’t want to draw Air back into the system, (I think that was my issue the first time). You also want to keep it as low as possible to promote good flow. A long Tube or arching it will draw Air in from the Discharge End. It will end up looking like this:


Start your Truck and set the Heat to Hottest and the Fan to Highest. Change the Mode to the Dash Vents so that you can feel the difference in Temperature. You will be able to see the Tubing between the Hood and Cowl. Watch the Air Bubbles and after it seems to stop, Rev the Engine a bit. It should produce some more Bubbles. I did this for about 20 Minutes, walking back and forth between watching the flow and Revving the Engine. I also squeezed the Coolant Lines a few times too. I actually missed being able to reach over to the Throttle Body and twist the Butterfly Valve by hand, oh well. You will feel the Air start to get Hotter.

I didn’t get any pictures of the Large Bubbles, but you can see here the stream of small ones. This seems to go on forever and truthfully mine wasn’t all Green when I decided to stop.



After 15-20 Minutes of this I decided to top off the Radiator again. I removed the Cap and poured in almost a whole Second Liter before I realized that I was filling the Reservoir too. Luckily I noticed this before the Coolant overflowed. It worked out even better, because before I finished up I just redirected to Tube back into the Bottle, until the Level was correct in the Tank. This shows the Radiator fitting where the excess drains out to the Tank. Once the Tank starts to rise, return the Radiator Cap.


I also shut the Engine off and listened for the Gurgling a few times to see how it was doing. After about ½ Hour I was satisfied for this occurrence. I have a feeling I will need to keep doing this till all the Air is flushed out. All the little Bubbles that the Water Pump turns into a Foam like state will recollect to big Bubbles over time.

To finish up, with the Engine running, I wiggled the Clear Tube all the way to the top of the fitting and then got the Cap ready up against it. I pulled the Hose and put on the Cap real quick then put the Clamp back on. This prevented Air from going back into the System. You will Spill a few drops, but I think its worth it.
Unfortunately I don’t have a picture of that since I only have two hands.

Shut down the Truck and your all done.

Not too bad right? Hopefully it puts an end to all the “Gurgling from the Dash’, ‘No Heat at Idle’, and ‘Heater Problem’ Threads that have popped up lately. Let me know if you guys have any questions.