I remember from many years ago I heard people always tell me to shut the air condition off before you shut the car off so when you turn you car on it is not on. .... Right now I have autostart and I want to know if it will do any longterm harm to my car if I leave the air on (because it I autostart my car in the summer 5min early w/ the air on by the time i get into the car it is already cool). I really need a firm answer on this because the hot weather is comming and I need to know the right thing to do. Also, if someone could answer why is it bad or why would someone say its bad to leave it on. Thanks

 

there is no harm in leaving your ac/heater on when you shut off your car. i have been doing that for about 10 years w/ all my cars and it hasn't done any damage. that is the whole purpose of auto start to leave your ac or heater on so when you turn on your car w/ your remote the car is cool/warm when you get it.

 

^^^ yea, no need to, but i have a habit of turning everything off before i get out of my car....wierd.....But thats me.

 

i always turn everything off. i like to get the engine running for awhile before i turn any extra stuff on.

 

I have been wondering the same thing ever since I got my auto start, so.... the way I firgure is this: even if your air conditioning or heating is off when you enter the vehicle, as long as it has been on for just a few minutes, then the cooling and heating will be faster anyways

 

the only thing i can think of is - its putting extra strain when you start the car but I do not know enough about cars to state that as a fact. I honestly have no clue why people say that but I remember always shutting off my AC before shutting my car off but it would feel so darn nice if i could go into my car ice cold when its 100deg. outside. Come on car experts --- both of us need knowledge!!

 

whether it's on while u start the car or off it's going to take the same amount of time to get cold

 

You let your car warm up for 5 minutes before driving in summer mornings?!!! That's gotta be the biggest waste of gas ever...do you also own an SUV?

 

i turn the key let it finish all the beeps then i turn the car on, sit there for about 20 sec. tops then start driving. i wait a min. or 2 before i turn the ac on, because by that time it should come out cool

 

They tell you about the a/c and radio because it drains the battery real quick right from the get go, and causes the alternator to crank out more juice before it's "warmed up". Therefore causing wear and tear on the alternator. For those of you who turn the car on to the a/c and radio full blast before the car has warmed up. LOL. ^ ^

 

The worst thing that could happen is after a very long time if an engine constantly idles it puts alot of wear on the valve guide seals which will eventually make it start smoking but were talking quite a ways down the road! hope this info helps.

 

i remember reading in the owner's manual that you shouldn't let your car "warm up" by letting it sit idle. I have no idea why that would be a bad thing though.

 

xx

 

I Used to work in a garage that maintains cop cars.

They would ALWAYS turn any car on, and idle for 5 mins before running it anywhere just to let the engine and internals all get lubed up.

Personally I don't do it on my car. Just get in and drive, and my car has run just fine.

But these people are professionals, there's no harm in letting your car idle before you drive it. (Except maybe 10 bucks a year in gas.)

As far as the heater or air conditioner, I'd imagine the only harm it would do is put extra strain on your battery at startup: That shouldn't be a problem so long as you don't have a weak battery.

Just my $.02 (and collectively those of about 100+ years of automotive mechanics I used to work with.)

 

anyone notice how the fan works? if you have the fan on, lets say almost all the way up, so you can hear it clearly. when you turn the key to the on position, the fan starts off low for a second or two, then it goes to full blast...this may be a built in feature, that would let the fan delay while you start the car, so you don't get blasted right away and so it doesn't draw any juice before you crank the starter. i believe everything turns off (except maybe computer fuelpump, distributor) momentarily when you crank the starter...

 

ok, did a lil research on my car about this whole subject. turns out the ac/heater is directly computer controled. it shuts off the compressor and doesn't turn it back on when you turn on the car until it is idling well. which means that it will not affect it.

 

Cool

 

one issue with leaving your AC on when you turn it off:

the condensor in your HVAC case will stay wet, from teh moister it.. well.. condenses.

this wetness can build up bacteria that can cause a stench.

best thing to do is turn off the AC and let the condensor dry off befre you let the car sit.

 

I heard that the freon or whatever cold stuff travels through pipes, well, if you turn off the car with the air conditioner on, then the pipes wear down over time, and a leak could eventually occur.

 

same.