A friend of mine experienced a bit of rain this past week and asked me why the heck does his car smell like old gym socks. Based on my experience only one thing can make a car smell like that – mildew. And the culprit – moisture.

It is quite natural for most older cars to experience this especially after driving in rain or slush. To remedy it quickly, you have to find the damp spots inside the car. Three of the most common spots for dampness are the cabin floor carpet, the car ceiling headliner and the trunk carpeting. If you notice damp spots in any of these, it means that you car is in need of some repair as water is getting inside. It might just be a need to replace the car’s weather strips or some serious body work repair if rust has finally made holes in your car, letting water get in.

In any case, to get rid off the smell, try to eliminate the damp spots first. If it’s the headliner, mop up the damp spot with absorbent cloth or chamois. Spritz on some anti-mildew solution and lightly scrub it on. Take a vacuum cleaner (capable of wet vacuuming) and vacuum the headliner to make sure that the dampness is gone.

If it’s the carpeting, take off all that’s not bolted on the floor – car mats and whatnot. Like with the headliner try to soak up the moisture with a chamois. Spritz on mildew solution, you might have to do some scrubbing with this. A soft nylon scrub pad will do. Again, vacuum thoroughly.

If it’s in the trunk, lose all that you have in there – carpet cover, tires, tools… If your trunk’s weatherstrip is the culprit, it’s likely that water has accumulated in the crevices of the trunk. Like with the carpeting, soak up, scrub and dry. You may want to spray anti-fungal solutions made for home use to prevent mildew from forming.

While not quite common, dampness in the floor matting especially near where your A/C motor is installed may mean that condensation may not be draining properly. Better check the drain hose for any clogging or foreign debris. You may consult you car’s manual where it is located (it’s commonly somewhere in the engine bay).

If you’re quite unlucky to get the smell after turning on the A/C that means that your A/C has been afflicted by mildew. Now this maybe a little complicated, I don’t really recommend you fiddling around your A/C if you’re not too sure about what you’re doing but the process may require spraying some anti-fungal solutions in the evaporator core and vents. Another friend of mine recommended turning on the A/C fan with the windows down, best done outside when the sun’s shining. But don’t stay inside the cabin, though, as you might inhale the mildew.