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3 Causes of Condensation In A Car And What You Can Do About It

Condensation on a car window. Do you constantly have condensation on your car window? Here are three major things that lead to condensation and some ways to tackle it.

The causes of condensation in a car can be a headache! They are not always easy to track down. If it’s only an occasional problem, recreating the conditions that lead to a damp interior aren’t necessarily simple to replicate, which can make it frustrating when trying to find a solution. Likewise, if it’s wet in your vehicle’s cabin on a regular basis, finding the source of the condensation in all the moisture can also be a challenge.

Let’s take a look at three of the most common causes of this condition, and what you can do to deal with the problem.

Soak It Up

It might seem obvious, but one of the main causes of condensation in a car is the presence of moisture that’s been trapped inside the passenger compartment. Often times it’s wet carpets or floor mats that end up being the culprit, as they sit low on the floor and can retain water that made its way into the vehicle on wet shoes, through a window being left open, or thanks to a clogged sunroof or windshield drain.

Condensation on glass

The key to dealing with this particular problem is to dry out your interior as best you can. Remove the floor mats and leave them lying in the sun, crack open your windows and park in a sunny spot, and if the water level is fairly high, try using a wet-vac to remove as much as possible. Always keep your vehicle drains clear, either by blasting them with compressed air or pulling out the leaves, pine needles, and other gunk that often clogs them up. Finally, make sure that the weatherstripping around your doors and windows hasn’t dried out to the point where it’s no longer making a seal on a rainy day.

Yesterday’s Coffee, Yesterday’s Wet Dog

Another often-overlooked item when considering the causes of condensation in a car is the effect of leaving old cups of coffee or open bottles of water in your vehicle. Over time these open containers evaporate, and the resulting moisture is trapped inside your vehicle where it can condense on your glass and dashboard. Clean them out and keep them out.

Other common moisture-bringers are wet clothes, umbrellas, or blankets that have been left in the vehicle — basically, any item that can transport water into the cabin where it sets up shop in condensation form. If you have recently been transporting a wet dog on a towel, for example, make sure to remove the linen from your car or truck once you get to your destination.

Heater Core Blues

The worst-case scenario for condensation in your car has to do with your heater core. If there are leaks in the core, small amounts of warm coolant can make their way into the cabin, or even blow up onto the glass itself, creating condensation. Usually, you can tell if you’re dealing with coolant condensation because the glass will feel somewhat greasy to the touch, and there will also be a sweet or glycol-like smell throughout the interior. Either of these signs means it’s time to head to a garage to have your heating system evaluated by a professional.

Don’t let condensation on the inside of your car hinder your ability to drive. Not only is constantly wiping condensation off of your windows a pain, but it can affect your ability to see the road. If you’re constantly having to deal with condensation, use this quick checklist to track down the causes of condensation in a car.

Check out all the interior products available on NAPAonline or trust one of our 17,000 NAPA Auto Care locations for routine maintenance and repairs. For more information on the causes of condensation in a car, chat with a knowledgeable expert at your local NAPA Auto Parts store.

Photo courtesy of Creative Commons.

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Benjamin Hunting View All

Having been bitten by the car bug at a young age, I spent my formative years surrounded by Studebakers at car shows across Quebec and the northeastern United States. Over ten years of racing, restoring, and obsessing over automobiles lead me to balance science writing and automotive journalism full time.  I currently contribute as an editor to several online and print automotive publications, and I also write and consult for the pharmaceutical and medical device industry.

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