I recently purchased a 2013 XJ supersport and changed the cabin air filter the other day. The reason I did is that there was that stale odor coming from the air conditioner for a few seconds after start up. The car was purchased in Long Beach Ca. as a 1 owner local trade in, i'm guessing the car was driven near the ocean.

For the most part it cleared up the odor except for a brief second at start up. I have not been able to find any info as to there being (2) cabin filters in this car so I'm assuming there is only one. If i'm correct does anyone have any suggestions on how to rid the odor on start up, or is there something like a filter sock that could have mildew built up on it ?

 

There is only 1 cabin filter located under the glove box. Since you've already changed that filter, there's probably some mildew or mold residue in the ductwork. To kill it, open the hood (bonnet) and spray Lysol or other similar disinfectant into the plastic outside air intake vents located near the base of the windshield. Run all of the climate modes - face, feet, defrost - to circulate the disinfectant throughout all the ductwork at various temperatures using both heat and air conditioning. Repeat as necessary until the moldy odor is gone.

 

Yes that's really the only way to kill the odor. Just be aware that once you get the smell it might take multiple attempts to get rid of it.

The only other suggestion I have is I find it works a LOT better to spray with the cabin filter removed. That's a big restriction.
I also spray into the cabin filter opening inside the car.
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After my first spray it has worked but not 100%, im going to spray with the filter removed

 

As I said, "Repeat as necessary until the moldy odor is gone."

I'm glad it worked for you.!

 

I've been trying something that might help the repeat from happening. Whenever I return home and park my car, I turn off the A/C, close air vents, and turn the blower knob all the way up. My theory is that will blow the remaining condensate out of the system & drain pipe and clear it. Welcome any opinion to my thinking?

 

Congratulations! You have just reinvented the wheel! Great minds think alike!

For many years, that's been recommended on the X150 Forum (XK/XKR) to clear the first design duckbill drain. Problem is that it doesn't always work. Also, set the air to recirculate and vary the airspeed.

Do you have water leaking into the driver or front passenger floor? If not, your A/C drain isn't clogged. Using this technique to dry the ducts to stop mold odor probably won't work because it doesn't kill the mold that causes the odor. That's why you need to use Lysol or a similar fungicide as I explained in my Post #2, above.

 

Check your AC lines for leaks, and I would also clean out the sunroof drains. They could be letting a little moisture in that is adding to the smell

 

AC lines contain R-134a NOT water!
Sunroof drains will get the interior of the car wet.

The problem is mold and mildew growing inside the AC ducts because of moisture. It certainly won't hurt to try and blow out all the condensate but not sure if it will make any difference or not?
I have always had to spray the system multiple times with disinfectant spray to get rid of the smell.
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