2001 Grand Am interior heats up without heater on

After driving for about 20mins, my car starts blowing a lot of heat on my feat (feels like the heater is on max) without me turning the heater on. Last time I had someone in my back seat and they said that it felt like I had a heated seat and it got hotter the closer we got to our destination. Can someone please tell me what is going on. I'm afraid that my backseat will catch on fire and I wont see it coming. I have a 2001 Gand Am SE 72,000 miles. No lights onn except the change oil light.

the fan is always on even though the heater is off. put it on cold setting and it wont be as hot. you can even switch the position of where it blows and it will still slightly blow

Like werm states, the fan is always going. I would, however have exhaust system looked at, as the rear seat heat issue is suspect. There may be a leak or something re the pipes that is conducting heat into the rear area.

Most likely you have your temperature selector in the hot range, even with the fan turned off air will blow in and be warmed (since you set the temperature to be hot)...remedy turn the temperature selector to full cold unless your cold.

Umm, heating up after 20 minutes? Sounds like a bad cat or other exhaust related problem, maybe a missing heat shield? I seriously doubt the heater being on hot, that would cause it after about 5 minutes or so, remember its summer and here in new england its been HOT for the past week or so..

^ That's what I was thinking. It sounds like cat is blocked, or a shield is missing, or maybe even a leak, which would heat up the floorpan / feets.

Yea missing shield or blocked cat would heat up the floor pan but the car is moving so a missing shield (which shouldn't be missing unless an idiot mechanic was under the car) wouldn't build up alot of heat. A blocked cat wouldn't really be felt by backseat passengers and if the cat was blocked the car wouldn't be running good.

If the car was twice it's age I'd jump on the exhaust bandwagon but a 2001 grand am isn't really that old to have problems like that but it is a fact that air does blow through the vents on the grand ams even when the fan is turned off, and I don't mean the slightest of air flow I mean you can feel it as if the fan was actually pushing air. If the heat temp is on hot the air coming out the vent will be hot and it'll flow enough with the fan off to heat up the whole car within 15 minutes. The reason I know this is because our '04 grand am works like that and you always have to adjust the temperature because cold air will come in the car or hot air will come out the vents there really is no "no air" setting except for turning the director select to max a/c so it shuts off the air coming from outside.

The heater setting stays on cold. The dealer told me about the fan issue. The heat problem on occurs on the driver's side of the car. The passenger side doesn't really feel much unless the windows are down and the wind is circulating the air. BUt someone said max a/c closes the vents? I'll try it.