Back to all

That Vexing Vapor Venting (Vapor Coming out of Vents)

July 7, 2025

You may have noticed sometimes on a hot and humid day, vapor will come out of your vehicle's vents when you have the air conditioning on.  Is that something to be concerned about? Well, it depends.

Sometimes that steam or vapor can be caused by water accumulating in the vent system after it has condensed.  And sometimes water can pool at the bottom of a vent.  When you turn on the blower mower, the air hits the water and may create steam or vapor that you can see in the cabin.

One thing to check is if that vapor smells like anything.  If it doesn't, that's a good sign. You may be able to run the fan for a while and the issue may just go away when things dry out.  But moisture collecting in the ventilation hoses in a hot vehicle may be a breeding ground for mold, and that can have health consequences.

There's another possibility. Ventilation systems often have drains to get rid of any accumulated water, and debris can sometimes clog them.  A technician can clean out those drains and you'll be back in business.

One thing to nose around for is a sweet smell coming out of your vents.  Sometimes the heater core (a component of your vehicle's heater system) can develop very tiny holes.  That sweet smell may be coolant that's been vaporized by those tiny holes entering your cabin. 

It's always a good thing to mention to your service advisor any abnormality you're seeing—or smelling—in your vehicle.  By venting a little about your vents, a technician can get to the bottom of the problem before it starts "clouding" the issue.

Star Lube Centerton
550 W Centerton Blvd
Centerton, AR 72719
479-795-1060
http://www.starlubecenterton.com

Need Service?

Request a Quote

More articles from Star Lube & Auto Repair

Keeping Your Cool (Coolant System)

March 29, 2026

No matter what the weather is like outside, your internal combustion engine expects to keep its cool all the time, even when it's really cold. That's because engines create the power that moves you to your destination by a series of tiny explosions of a fuel and air mixture. In turn, that genera... More

Automotive Tips from Star Lube Centerton: Alignment Inspection

March 22, 2026

Uneven tire wear, the car pulling to one side or a steering wheel that is off-center are signs for Centerton drivers that their wheels may be out of alignment.When doing an alignment inspection, the service advisor at Star Lube Centerton will inspect your tires for uneven wear as well as suspensi... More

Your Biggest Fan (Radiator Fan Problems)

March 15, 2026

Your vehicle's engine makes a lot of heat when it's powering you down the road, so it needs a way to get rid of that energy. That's why your vehicle has a cooling system, complete with a radiator and one or two radiator fans, also called cooling fans. Those fans make sure air keeps moving acros... More