[uke]

So this is tied directly to the duration of the drive? 45 minutes, 55 minutes, no temp increase, then suddenly at 60 minutes you get a blast of hot air from the footwell?

The MINI is little mobile greenhouse, with lots of window area. That and a black roof mean the interior (also black, I venture) heats up aggressively, especially in the summer sun. If you park it in the sun it will get hot, that's normal.

But a sudden blast of hot air after driving a specific, same period of time is very odd.

 

[uke]

I truly believe that there is a problem with the car, but as I am a woman and don’t understand much about cars, the dealer will keep telling me that it is the type of the design that makes it hot.

Woman or not, you should not have to troubleshoot your car's issues on your own, especially while it is under warranty. If you think they are patronizing you because of your gender, I bet you could have them for lunch.

I have a 3 door S. The hood scoop is vestigial, it does nothing. The automatic climate control on my car performs flawlessly, even in Arizona. Something is screwy with your car.

I wonder if the car thinks that the temp is way cooler than reality, and is deciding to heat the interior up? From what I've seen on the auto AC, in automatic mode it will direct warm air to the footwells if it thinks the inside is cooler than the set point. So I'm wondering if the interior temp sensor is catawampus somehow?

How could that happen? What if the pipe that pumps cool air into the glove box came loose, and is blowing frigid air on the back of the sensor? See this thread, where the AC pipe actually fell off into the footwell. The sensor gets it's electronic patootie frozen off, and the Auto Air Control tries desperately to heat the interior up. On the attached picture it's part 12.

This would fit with the hour delay before the inferno kicks in-- it takes that long to cool the sensor to that point.

Dos this happen when the AC is on Auto and also when on Manual? If it only happens on Auto, this could be what's going on.

 

[uke]

Having been fortified with the correct amount of fine red wine from the old box, I now think experiments could be performed to validate what might appear to be a crazy Random Internet Yahoo theory.

Experiment 1:
Apparently you can reach behind the dash and feel both ends of the little pipe that sends cold air to the glove box. Start the car, turn the AC on, and after a minute feel around. If you feel a blast of cold air on your hand near the center of the console, near the end of the pipe, try and detect the direction it's flowing towards. On the lower console there are a bunch of push buttons for the various environmental functions. In the center there's this weird little rounded nubbin; that's the cabin air temp sensor. If the cold air you feel is blowing towards the back side of that sensor (or where you imagine that sensor might be from behind), that's evidence that my crazy theory might have merit.

Experiment 2:
Feel the sensor after driving for a while. Is it colder than the rest of the dash? If it is, supports nutso theory.

Experiment 3:
When the heat inferno starts, place your finger on the nubbin and hold it there. If my theory is correct (or even if my theory is stupid and it's just a sensor issue), the heat blast should stop as the sensor warms up and reports the cabin is no longer at -40 C. Uke suggests a helper for that so you don't drive distracted. Also, YMMV; if you're cold-blooded this may not work because your finger is no match for Precision Bavarian Air Conditioning Run Amok. Find somebody with a warmer appendage.

Experiment 4:
Play with A/C settings. if this happens even when manual A/C is selected, that means that the auto system isn't trying to fix a cabin temp/set point discrepancy. It's something else.

Select manual mode, and then adjust it so that the system is blowing mostly through the upper vents. If that air is cool, but you're still getting heat from below, it might indicate that a valve has glitched in the heat exchanger, or an air valve has stuck. Try every combination of settings, preferably with a MINI Minion sitting beside you. If anything doesn't make sense, its a clue. If everything works great in Manual Mode, but as soons as you switch to auto the barbeque starts, then that's another clue that evil software is involved.

I don't think this is a problem with insulation or the exhaust system under the car. If that were the case, then as soon as the car reached operating temperature the heat would be blasting through and warming up the footwell.. But Ms Burning, esq reports this doesn't happen until after an hour of driving. That tells me that this isn't an insulation failure or an overheating issue; it's a software/sensor/physical computing system failing to correct for the failure of one or more components. My WAG is that the glovebox A/C pipe has loosened and is messing up the cabin air temp sensor. Or that the sensor itself is whacked.

If it turns out to be something entirely different, I will eat vegetarian crow and seek solace in my box of fine wine.

Thoughts?

 

[uke]

Uke you're amazing. Great of suggestions.s. this may really help her as there must be something wrong with the car or the sensor blowers system
.

Thanks, Jeremy. I can't help myself; I'm a software engineer. Debugging weird glitches is my life. I am compelled to find the Devil In Her Car.

 

[uke]

Thank you for all the comments on the issue of my MINI. I'll try to be more specific with the problem that I have had with my MINI. Please forgive my poor vocabulary that I have with cars. I usually I fell more cold than others because I have very low blood pressure. So, I avoid using air conditioning as much as I can. The hot air seems to come from the engine. It's not that I feel in the sole of my feet, but in the top of my feet and in my legs. As an example; 2 months ago, it was 60 degrees outside and inside of my MINI when I started driving. I drove for approximately 45 to 60 minutes; than, I stopped for 30 minutes and by the time I went back to the car to drive back home. Inside of the car was 80 degrees. I did not use the heating while driving, it was not sunny outside, and by the time I parked the car, the outside temperature was 59 degrees. So, it was 20 degrees higher than the outside temperature when I started driving back home.

So, what I have done lately is to turn on the air conditioning in the feet area as soon as I start driving if I will drive longer than 1 hour. Please note that no, the hot air doesn't start exactly after 1 hour driving, but around that time.

I'm kind of confused. It sounds like you are describing two issues-- First, a mysterious sudden blast of heat that you can feel upon your legs after driving approximately 60 minutes. Second, the interior of the car heats up when parked in the sun.

The first issue sounds like the footwell vents are blowing hot air on you. That would definitely come from above. If you felt it on the soles of your feet instead, that would be an entirely different problem.

The second issue is normal-- it's the Greenhouse Effect. It can be near freezing and the car will still warm up inside due to heat from sunlight being trapped by the window glass.

Do you think that the heating of the entire cabin after parking the car is caused by, or somehow related to, the sudden heat that you feel while driving? (One way to test that would be to drive at night-- Does the car heat up when parked in the dark? All cars will heat up a little bit due to radiated heat from the engine bay, but not dramatically).

Important question: Does this happen when the system is on Auto mode, or Manual mode? Both?

 

[uke]

One additional note on the Greenhouse Effect; it doesn't have to be sunny for this to happen. The car will still heat up under a cloudy sky, albeit more slowly.

Also, you said that you don't run the A/C-- Do you use the defroster at all?