Back to all

That Vexing Vapor Venting (Vapor Coming out of Vents)

July 14, 2024

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.

Tuffy Tire & Auto Service Glendale Heights
1153 Bloomingdale Rd.
Glendale Heights, Illinois 60139
630-588-8846

More articles from Tuffy Glendale Heights

Lean Times (Shocks and Springs)

October 12, 2025

You may have noticed your vehicle going through lean times. By that, we mean it's literally leaning to one side. When you notice that, you should get it checked out at your service facility soon because you could have a serious problem. Many things can cause a vehicle to lean. You may have pro... More

Out of Joint (CV Joint and Boot Replacement)

October 5, 2025

If you have a front-wheel-drive vehicle, it has components called CV joints which enable you to turn your wheels smoothly. The CV stands for constant velocity. In essence, its a set of gears that connect a shaft that allows power from the transmission to be sent to the wheels. When you turn the ... More

Why is My Brake Pedal Hard to Push?

September 28, 2025

When you push on your brake pedal, you should find your vehicle easy to stop. But at some point, you might notice stopping takes much more pressure on the pedal than it used to. When it gets to that point it becomes a safety issue, and you should bring your vehicle in so we can track down whats... More