I recently purchased a 2014 Acura RDX Tech Pkg. I've begun to notice that when I don't have the heat or air-conditioning on, the interior of my car begins to heat up by itself. I'm pretty sure it's because of the engine. Is that normal?

 

Are You sure it's not the exterior color of the car?I have never noticed heat from the engine internally.But,Brown heats up quickly in the sun.I had a Champagne color in previous SUV.The RDX gets warm much faster in the sun.

 

would the exterior color affect it? I don't mean like when I first get into the car because it's the winter time and the car is cold. After driving for a while, the interior gets pretty warm. I have a kona coffee (brown) color. I can feel the heat coming from the vents even though I don't have the heat on.

 

you might have to tear into your center console and check out if anything is loose or disconnected where you feel the heat coming from.

 

It is automatic temperature control.You can turn it off,why I don't know.If You see a number in the display for driver and passenger it is on and will automatically heat when inside air is colder than outside air.Most people don't know that A/C is always on ,unless You shut it off.

 

I realize that. The numbers are never displayed when the problem occurs. Unless, the auto temperature control is active when the numbers are not displayed.

 

What I noticed is the the center console makes a slight noise. I figured that the noise was normal because of the navigation system.

 

Sorry to be so basic,but it is a new car to You.I have never shut the temperature system off as I always want air movement.I will shut it off today at 54 degrees and see what happens.

 

I'm purely speculating and what I would do if I noticed or felt something that wasnt supposed to be....
i'm inquisitive and handy and would have no problem tearing into something to see if thats how its supposed to be.
in other words, investigate further if you feel its not right

 

I could be completely wrong on this, but this sounds like any other car out there. Even though the climate control is off, a small amount of air still moves through it. If your temp setting is on high, a bit of warm air will continue to enter the cabin. I've yet to see a car NOT do this.

 

I have a car very similar to the OP. Honestly I've never noticed any increase in heat. But now that you mention it I'll keep checking for excess heat. Now that the winter is coming any extra heat will be welcome. .

 

I turned off the temperature control today.Drove for an hour in 55 degree on cloudy day.I did notice heat blowing from lower heat duct.Can't tell if it is engine heat or heater core heat.It would only blow when moving,so it is car motion that causes air movement.It did not get uncomfortably warm.With the temperature control on the lower duct was actually cooler than without temp.Probably because fan was running.I can't say that this a problem.Certainly not for Me,since I never turn the climate control off.I do turn off the A/C.

 

Press recirculation button. Does it stop?

 

In a vehicle with a manual HVAC system, the fan draws outside air from the grill at the base of the windshield and downwards through the cabin filter. The temperature selector on the dashboard pulls/pushes on a cable which moves a door to deflect various percentages of this air through the heater core. In an automatic system, like on the RDX, the computer sends the signals to move the door.

When any vehicle is in motion, the air hitting the windshield is forced downwards through the grill at the base of the windshield. This air then passes through the cabin air filter, into the interior of the vehicle. The resulting pressure buildup inside the vehicle is relieved by vents in the rear of the vehicle, which let it pass to the exterior.

In other words, when a vehicle is moving, air is passing through the cabin filter even when the fan is not operating. Of course in recirculate mode, no outdoor air is allowed in.

So here is my theory on your increase in temperature. When you "shut off the system" what temperature setting did you have?. If you had the temperature set fairly high, the damper doors were set to force more air through the heater core. When you "shut the system off", it's quite possible that the door just stayed were it was. As you drive along, the normal air flow is passing through the heater core and warming up the interior.

As a test you could set the temperature to minimum before "shutting off the system" or set the system in re-circulation mode before shutting it down.

 

I agree with RDX-Rick. When my '17 has a temp set to, for example, 72, and the system is 'off', I can drive off in the early AM here with the temps in the low 30's and you can feel some heat coming into the cabin. If I lower the temp all the way down before I shut the system off, there is no more heat coming in, unless I raise the temp on the system.

 

I usually keep it set on high because it's the wintertime where I live. I'll try your suggestion about setting it lower. Thank you.

 

^this is normal operation of a car.

 

Okay, so I set my temp to about 70 degrees instead of high today and turned off the climate control. I haven't noticed any excess heat coming from the vents. Thank you all for the input.

 

Boom, car functioning as it should !

 

OP posted what I was going to say

even when the HVAC is off there is still some airflow through the system as the car is ventilated. does the problem go away when you hit the recirculate button, if so, just set your temp lower before you turn of the HVAC. HONDAS have a long history of this (decades) type of behavior... My Subaru does it as well but even with the HVAC off I can still adjust the temp as I have a manually controlled HVAC.... a lot of cars direct the ventilation when the system is off through the door defroster vents so it is not as noticeable... Honda/Acura is no one of them.