Is it safe to sleep in my car and leave it on all night?
Posted by Guilty_Anything7606@reddit | askcarguys | View on Reddit | 238 comments
Hello.
I know people usually sleep with their car off but i’d rather keep it on as it’s quite hot where I live. I will sleep from 3 am- 8 am, but will have it on from now (10 pm).
Will this drain my battery even if i close the outside light?
Thanks.
cmbtmstr@reddit
Idling for hours on end builds up carbon on the piston and valves because the engine doesn’t get to a hot enough temperature (like it does during hard acceleration) to burn off the deposits. Honestly I can’t tell you how soon that would actually become a problem but it would likely be years down the road rather than doing this for a few months until you find a different living situation.
You will definitely need to increase your oil change intervals. Try to find a conversion between hours idling and how many miles that equals per night of idling. Use that to determine when oil changes should be done by adding the mileage from hours idling + miles driven from least oil change.
I just got back from drinking w friends so not sure if that made sense but if it didn’t please ask and I can try to explain it better when sober.
Guilty_Anything7606@reddit (OP)
I don’t really drive much anyways. Like I was “due” for an oil change in february after getting it changed in november, and my oil levels until now are still good. People have been saving even for an hr it gets damaged? But i car rot for like 1hr-2 everyday and Im not sure if it’s been damaged yet.
choppysmash@reddit
Those people are over exaggerating how much idling wears out the engine faster. It will increase wear but doing what you describe, the wear is negligible as long as you change your oil more often. If Mazda says to change it every 10,000 miles or one year you should do it every 5000-6000 or 6 months whichever comes first. (Idk what Mazda specs for oil change intervals I’m just using the specs from my car as an example).
Since you do idle a lot make sure you occasionally accelerate hard through a few gears when it’s at operating temperature. Should help with any deposits that accumulate from extended idling. Look up what an “Italian tune up” is.
Guilty_Anything7606@reddit (OP)
it’s 5k.
like just push the gas before i turn it off?
choppysmash@reddit
No when you’re driving push the gas pedal to the floor and accelerate quickly a few times (with the engine already warmed up don’t do it when it’s cold). Do this on a highway on-ramp or some place where it’s safe to accelerate hard. Think of it like you’re exercising the engine. You don’t want to do this all the time but once in a while is good.
cmbtmstr@reddit
Maybe pushing it to the floor is a bit much but if you're driving normally, the car probably shifts around 2.5k to 3k rpms. It's beneficial to occasionally push it a little harder. Pressing the gas pedal down farther will make it shift later in the rpm range. So under harder acceleration, it will probably shift around 4k rpms. That should do the trick to help clean the carbon buildup.
cmbtmstr@reddit
Ah, so oil doesn’t just need changed when it gets low. Oil also needs to be changed based on the time since last oil change and the miles driven. Or in your case considering the idle time as well.
This is because over time of circulating the engine while running, oil breaks down and becomes less effective at lubricating parts of the engine. It’s also a good idea to change it every 6 months even if you don’t drive it that much because the oil is still sitting in the engine picking up contaminants.
The amount of miles you should go between oil changes is different between the type of oil that you use. If you go to a cheaper place, they will give you the cheapest conventional oil that will last 3,500 or 5,000. They will tell you how many miles the oil is recommended to be changed at.
Now for what I mentioned last night, I looked it up and most fleet service vehicles that idle a lot (think cop cars, taxis, etc) treat one hour of idle time as 30 miles of driving in terms of maintenance on the engine.
So 8 hours of idling would be the equivalent of 240 miles of wear following that recommendation.
My suggestion: if this is going to be a regular thing, I would recommend learning to change your oil yourself if you do this. Find a YouTube video that shows how to change it for your model of car. There are plenty of great ones. You can purchase all of the tools needed to change your oil at Walmart and you can purchase the oil + oil filter at Walmart as well.
Why change it yourself? Because you can put higher quality synthetic oil in your car that lasts 10,000 miles (as opposed to the 3,500 or 5,000 that the shops put in your car).
If you’re using a 10,000 mile synthetic oil like Mobile1 then you can get away with doing an oil change every month and a half as opposed to changing it every 2 weeks with the cheap stuff the shops put in (since we’re factoring in 240 miles of wear on the oil per 8 hour night idling).
Guilty_Anything7606@reddit (OP)
don’t wanna edit the post but the car is a mazda cx5 2015 if it makes a difference.
Just-Flounder-326@reddit
People saying it's bad for the engine means if you do it for years it won't last as long (but they usually just look at miles not engine hours, so they're doing bad stats anyway). I've idled my car for hours in the heat for a/c and for hours in the winter for heat and it still ran for 150k, and that's in an older Subaru. The Mazda is going to be fine and you won't notice any effect. Half the people up north idle their cars every morning for a half hour just to get it toasty and there's plenty of old cars still running up there. Your battery will be fine, the AC compressor runs off the engine.
The comment saying change the oil a little more frequently with lots of idling makes sense, since your putting hours on the engine but not getting any miles.
Just-Flounder-326@reddit
If you wanna be extra safe just leave it off recirculation so you're getting fresh air all night. But even with recirculation on is essentially just the same as sleeping with the car off and the windows up. The co2 builds but cars are leaky, so shouldn't be a problem. I guess newer cars might seal really well but I've never heard of it being a problem.
choppysmash@reddit
Idk about Mazda but some cars will cycle to fresh air periodically if you leave them in recirculating mode to replace some of the “stale” air in the cabin. I know BMWs do this for sure but I’d be shocked if they’re the only ones who do.
Guilty_Anything7606@reddit (OP)
what’s the best button to keep ac on
choppysmash@reddit
The A/C button. That will run the compressor which is what makes it blow cold air and helps get rid of humidity.
magichobo3@reddit
Honestly it'll be fine, it's just like if you drove 10 hrs. If you're doing this regularly you'll want to check the oil and coolant levels much more frequently and probably want to change them more often than you would due to mileage
Guilty_Anything7606@reddit (OP)
Someone said it’s like 100 miles or something in just an hour? I car rot often like one hour to 2 like everyday. Have I been damaging my engine!?😭
bradpliers@reddit
I don't even let my car idle for more than a few minutes without feeling bad.
Guilty_Anything7606@reddit (OP)
i start feeling bad so i turn the ac off for a bit lol.
choppysmash@reddit
If you’re turning the AC off you may as well turn the car off unless you’re still running the blower motor without the AC on which would drain the battery fairly quickly.
Keep in mind lots of fleet vehicles spend hours idling and while it does increase wear in the engine it’s not like one night of running it will blow it up.
CO detectors are like $20-30 for a basic one but your car is new enough that I seriously doubt it’s a risk if you’re parked out in the open and you don’t have any exhaust leaks.
Guilty_Anything7606@reddit (OP)
What’s a blower motor?
choppysmash@reddit
It’s the fan that blows air through your vents. You can have it on but your AC off.
cmbtmstr@reddit
For fleet maintenance on cop cars, 1 hour of idling is treated as 30 miles. You have not been damaging your engine by sitting in it 1 or 2 hours. I sit in my car for an hour or so a day since I was 16 (that was 9 years ago) and the car is still running fine.
Hash-82@reddit
The rule used in fleet maintenance is 1 hour idling = 17 miles driving.
I'm sure there is variance, and I'd think the CX-5 1.5L would be less.
I'd probably use 15 miles / hour just to keep the math simple.
But, you're already months overdue for an oil change already
Tinchotesk@reddit
An idling car uses about a litre an hour. Long idling is not ideal for the engine, but it is not a big deal if everything's work as is supposed to.
Paqza@reddit
Idling your engine is much worse for it than hitting an onramp (with a warmed up engine) and driving on the highway at 70+ for an extended period.
Guilty_Anything7606@reddit (OP)
😳😳i love car rotting. this is so sad to learn.
thriftyoleboy@reddit
Bad idea. You never know. https://gulfnews.com/world/gulf/oman/four-expats-die-from-carbon-monoxide-poisoning-inside-vehicle-in-oman-1.500541690
dg8882@reddit
Nothing will be seriously hurt, but those idle hours are still putting wear on your engine and everything else thats in motion. Consider changing your oil earlier if you do it often and parts of the like the AC or water pump could fail sooner than expected.
Guilty_Anything7606@reddit (OP)
Everyone is saying to change the oil earlier. Is this a one time thing or everytime I will need to change it earlier?
BisexualCaveman@reddit
What model of car?
Some of them will tell you when to change the oil, and are capable of factoring in how much you idled.
There was a woman I saw online who had a Chevy minivan that kept telling her to change the oil every 2,000 miles.
Turned out that she was driving her kids to and from school and spending a whole bunch of time idling because she would get to school and wait, in the Texas heat, for her kids to actually get out.
Guilty_Anything7606@reddit (OP)
Mazda cx5 2015.
I changed my oil when I got it in november. I only drive short trips, max 20 miles (to and from), and i idle for an hr or 2 quite often.
I was “due” in february but haven’t needed to get it done. My oil is still at a good level. It’s been a long time though. Might just change it for funzies at this point.
I lowk smell a light gas smell so might go inside lol.
BisexualCaveman@reddit
Okay, check your manual, but my understanding is that most Mazdas do have an intelligent oil life monitor feature.
Make sure it's turned on, too.
Guilty_Anything7606@reddit (OP)
Yes supposedly my car has one. It never went off so far. I know how a car drives when oil is low, so even if it didn’t notify me i’d most likely get it checked anyways. The car drove a bit weird like a month or 2 ago so I got it checked but it was completely fine. I heard mazdas are crazy reliable and I guess after having a bmw and a nissan, my brain is just so hardwired not to believe it lol.
To turn it off on, that would also be in the manual?
BisexualCaveman@reddit
Turning off and resetting the "time to change the oil" alarm, if you have one, would be detailed in the manual.
Guilty_Anything7606@reddit (OP)
thanks!
Guilty_Anything7606@reddit (OP)
i googled it and it says my car doesn’t have a low oil sensor, only a low pressure one, which isn’t safe to wait for. so i have to manually check the oil each time.
i never really learned to take it in and out, so i’ll probs go to take 5 and have them check. though i’m not getting it changed with them anymore found a cheaper option.
BisexualCaveman@reddit
I was talking about the thing that tells you when your oil is worn out, not low.
Guilty_Anything7606@reddit (OP)
ah my bmw and nissan had a sensor that would tell me when the oil was low not the pressure.
MaxPanhammer@reddit
Hi, I know this whole post is crazy and this will get lost but please change your oil. It doesn't matter is it's "low", oil changes aren't for low oil levels, engine oil breaks down over time and becomes less effective. You could go WAY longer than the recommended interval without having low oil levels or warning lights but basically destroying your car (especially if you're doing a lot of idling in the heat)
It's one of the most effective things you can do to keep your car running well for a long time.
Guilty_Anything7606@reddit (OP)
Hey yes i know. Thats usually what I end up having to do because i rarely get to the point of needing one. I know it starts going bad so I do end up changing it. I’ll probs do it when I get my next paycheck.
guffy-11@reddit
Wow! You mean waiting in the car while they were at school?
dg8882@reddit
For every hour you idle, add 33 miles. Your odometer might not be going up but your entire engine is still feeling the wear.
munjavio@reddit
Yup, why heavy duty trucks and diesels have hour meters along with the odometer
Cyka_Blyat_47-74@reddit
Your scenario is perfect for an EV.
Guilty_Anything7606@reddit (OP)
it’s just a one time thing electric cars aren’t sustainable in my state.
dandanthetaximan@reddit
I don't think the word "sustainable" means what you think it means.
Guilty_Anything7606@reddit (OP)
i quite frankly do. sustain literally means to support, maintain, or keep something going over time. i explained it’s literally not sustainable in my state. we have constant power outages and no charging stations. literally would be a nightmare having one here.
choppysmash@reddit
Are you in a very rural area? Charging stations are popping up all over the place across the US. And if you’re only driving 20 miles per day you’d maybe have to charge once or twice a week at a fast charging station. And that’s assuming you can’t plug in at home.
Guilty_Anything7606@reddit (OP)
the only charging station we have here is like an hour or more away. i’m not going to drive an hour or more just to charge a car lol.
bearcassidy@reddit
Jesus Christ. The answer is yes, it’s safe. It will not drain your battery even with the lights on.
These people sound like ChatGPT never answering the question directly and giving unsolicited, irrelevant advice.
Guilty_Anything7606@reddit (OP)
wow i just woke up 216 comments is insane 😭. the arguing must’ve gotten insane after i knocked out
professional-paradox@reddit
The two biggest concerns are carbon monoxide poisoning and the car overheating if its cooling system isn’t up to par.
If the exhaust is correctly routed away from the car, then you should be good. But exhaust leaks from improper sealing of pipe joints under the car can let exhaust out under the car and let it rise up into the cabin. If the exhaust lingers right next to the car from no wind, that can be a problem too.
Cooling wise, if the car can idle for an hour without overheating, it should be good I think. As long as it’s topped up on coolant and the radiator fan(s) work, it should be good in theory for that long.
Working_Strength419@reddit
Waste of gas, bad for environment, bad for engine, I wouldn’t do it. Just shut it off and sleep. If your cold get a blanket, if your hot suck it up or get a fan
Particular_Good_8682@reddit
As in engine running or just ignition?
But tbh both a bad idea for difference reasons 😂
Guilty_Anything7606@reddit (OP)
engine running
matthewxman79@reddit
Just make sure you change the oil way more often. I forget the math, hopefully someone will correct me if I’m wrong, but I think it’s like for every hour idling is like 30ish miles driven. Keep that in mind for oil changes and it won’t be as bad as people say.
cmbtmstr@reddit
Yep, exactly. For fleet vehicle maintenance, 1 hour of idling = 30 miles on the engine. Changing the oil sooner is the biggest concern in my opinion as long as the car does not have any issues with the radiator that make it overheat
7eregrine@reddit
You want to leave the car running all night? Why would that kill the battery?
Idling for hours isn't great for the overall health of the engine, but I'd say it's safe enough in the right environment.
Guilty_Anything7606@reddit (OP)
Yes running. I don’t know that’s why I came on here to ask lol. I know if you leave the light on all night, it’ll kill the battery (past experience).
How can I do it safely?
7eregrine@reddit
An idling engine will keep your battery charged. Just keep the lights off. You'll be fine. You're not shaving.yeara if life off it as someone else said. Just change the oil more frequently.
ImFromTheDeeps@reddit
You definitely are. The vehicle is designed to cool with air going through the rad. The engine will be running pretty hot. Leads to a lot of issues over time. Doing it once isn’t bad but over a span of time it hurts the engine.
CheefReetard@reddit
Radiator fans are a thing
ImFromTheDeeps@reddit
Ya if its hot out already wtf is a fan gonna do, blow hot air on the rad. Jesus.
TrifleImpossible5997@reddit
And thermostats
mondaymoderate@reddit
That’s not the problem. An engine is designed to idle indefinitely. The thermostat and radiator fans will keep it at operating temperature. The problem with idling for a long time is that fuel doesn’t burn as efficiently and that washes the cylinder walls.
ImFromTheDeeps@reddit
You're wrong. Without the forward motion of the car, less air flows through the radiator
. Prolonged idling can strain your cooling system, overheat catalytic converters, and cause plastic parts under the hood to warp or crack.
this is direct from google which you're free to use.
clvnblnkee@reddit
It'll burn at stoichiometric as long as you have closed loop o2 feedback which all cars do post 1996.
TrifleImpossible5997@reddit
If it's summer time and they're running a/c, it's probably burning plenty efficiently
That only happens in cold weather where idling won't get it to operation temperature
TrifleImpossible5997@reddit
That's what radiator fans and thermostats are for
Guilty_Anything7606@reddit (OP)
I thought to charge the battery you need to drive not just park. I turned the lights off right away lol. When I had my first car I accidentally left the lights on all night and woke up to a dead battery AND alternator😭.
BisexualCaveman@reddit
If a car is properly maintained and without defects, it should be able to idle for an entire tank of gas without running the battery down.
Your prior vehicle probably had a bad alternator to begin with.
Guilty_Anything7606@reddit (OP)
most likely yeah. the 2 previous owners just let it sit for years without using it. it was also a bmw. now i love bmw but i would never own one unless i was filthy rich. i got it for 5k it was a bmw x5 2005. it’s been dead in my driveway for a few years now due to the transmission giving out. it was, sadly, my first car so i miss it from time to time but i dont miss the damn money i spent fixing it for no reason.
ApoTHICCary@reddit
Should be the ZF 5HP24 5 speed automatic in your e53. There’s one for sale right now on the forums for $600:
https://www.bimmerforums.com/forum/showthread.php?2500475-ZF-5HP24-5-speed-automatic-transmission-out-of-E38-740i-M-Sport
The e53 x5 is a great platform and pretty reliable, but takes a little higher pedigree. You cannot neglect maintenance items, but otherwise they’re know to run for a long time without issue when maintained properly.
Guilty_Anything7606@reddit (OP)
I’ve always properly maintained all my cars. I’m on my 3rd one now. I’m only on my 3rd because the first died from the transmission. The second car, the first owner totaled it and lied about it. I was then in an accident (not my fault) and that’s when i found it and it was deemed totaled again. Then i got into another one (also not my fault just shitty ass luck) and that time it was totaled as hell. I’ve had this car since Nov.
Honestly, back then I could only find transmission for 10-15k, so I gave up. I then found a used one for 1k but after some thought, I genuinely didn’t want to fix it. Sure I can fix it but I’ll just constantly need to pay for fixes. I fixed the radiator THREE FREAKING TIMES, and it kept breaking. It needed oil changes so often and they were always like $150. I constantly needed to put expensive anti freeze. Just too much of a headache. I miss the sound system that was installed into it from a previous owner though. It’s genuinely such a nice car to drive in but not worth the headache if you’re broke.
ApoTHICCary@reddit
Those transmissions do not cost $10-15k new. It’s a rudimentary automatic made by ZF and features in quite a number of cars. They’re not special or sporty. Again, there’s one for $600 currently. But I understand that shops were trying to take advantage of you. Look for independent shops that work on BMW. They’re more honest and far cheaper.
3 radiators is unusual. The OEM radiator is not known to be faulty, but it is a wear item so they will need to be replaced at its age. Likely the radiator was swapped for an aftermarket unit which are lower quality than BMW OEM. There are some aftermarket parts which are quality. I buy most all my parts thru FCP Euro as they are quality and offer lifetime warranties on literally everything. If the radiator goes out, you send it back to them and they send you another.
Oil changes should not cost $150. Again, nothing special about it; it’s an X5. Oil change places will take advantage of you. You can buy an oil change kit off FCP Europe and send back the USED oil and filter as their LIFETIME warranty also covers fluids. Yes, you pay once for the kit then $30 to send it back for another oil change kit. Brake pads are the same. They have a lifetime warranty on just about everything.
These cars are quite reliable and very affordable when you are utilizing the right resources.
Guilty_Anything7606@reddit (OP)
I knew they would try to scam me since it’s common to scam girls since we’re “less knowledgeable,” so I had males shop around for me. I also went to 6 different mechanic shops and the lowest quote was the $10k. Maybe it’s dependent on state. Everything car related in my state is expensive as hell. Our gas is $4 so in that regard, not more expensive than other states like california.
They were all independent shops but one. The one was the actual bmw mechanic shop we have here and if i remember correctly im pretty sure he damn near quoted me 20-25k lol.
I don’t know if you saw my other comment but the 2 previous owners treated the car like shit. They just left it sitting for years and never maintained it or drove it often. I got it at like 138k i think, and it lasted me until 170? The radiator pipe or whatever kept getting loose. I changed the radiator itself 2 times, and the pipes maybe like 4. It just kept being faulty. I always had a leak. At one point something was wrong with the oil thing and I had to change that out too. So many things went wrong with that car.
The oil changes were that much because it took a bunch of extra gallons. It was take 5 so i’m sure they upcharged. As a girl I decided to use my own powers for good. I always go there till now to pump my tires, fill fluids, and such. Each time i’d go and chat about random things (i never flirted but they would always obviously flirt), after some plotting each time I would go they ended up giving me big discounts lol. I once got an oil change for $30🤣. My mechanic actually does oil changes and he doesn’t charge much so I won’t be going to take 5 for oil changes anymore. I will however still go for fluid checks and to get my tires pumped. Why miss out on a free service lol.
Bmws are known to be nice lavish cars, but not reliable. They’re very expensive to maintain, and if you don’t have the funds for it they’re a horrible car to own. Bmws have been my fav car since I was a kid, but until i’m filthy rich I’ll NEVER own one again. The drive and literally everything else about the car is irreplaceable. I have never been in a car as good as a BMW. It’s unbeatable. It’s just not worth the constant fixes. I always maintained it, but due to past owners it was pretty much useless.
Occams_RZR900@reddit
You probably had a dead alternator first, then the battery died.
Guilty_Anything7606@reddit (OP)
most likely yeah. the 2 previous owners just let it sit for years without using it. it was also a bmw. now i love bmw but i would never own one unless i was filthy rich. i got it for 5k it was a bmw x5 2005. it’s been dead in my driveway for a few years now due to the transmission giving out. it was, sadly, my first car so i miss it from time to time but i dont miss the damn money i spent fixing it for no reason.
Klar1ty@reddit
your alternator was toast, that’s what charges your battery. that’s why your battery wasn’t charging when you left your car on
Strange_Produce5601@reddit
An idling engine will not charge the battery much. So running accessories like lights and the radio can absolutely drain a battery over time.
gtiguy12@reddit
Maybe a car built in 1950. Most modern cars make more than enough amperage to keep the battery charged at idle. More modern cars have pwm alternators that can increase the output at any rpm.
Strange_Produce5601@reddit
a quick google search shows me otherwise. I can not find any concrete evidence that a battery will be charged efficiently while also being drained by cars electronics while at idle.
gtiguy12@reddit
Dude, I work on cars for a living. The smallest alternator you are going to find on a car these days is 90 amps. A 10 Amp draw from the ecm 20 amps from the fans and 20 more amps in misc lights and a/c isn't enough to out work an alternator at idle. Don't use Google to answer questions. Use experience.
External_Capital1753@reddit
Running a car at idle isn't efficient, it doesn't mean it won't power a blower fan.
Heavy_Gap_5047@reddit
Did you find evidence that it won't?
WhichDragonfruit2896@reddit
Did you just ask for evidence of a negative?
Heavy_Gap_5047@reddit
Yes
Ok-Huckleberry1970@reddit
At idle 99% of vehicles will stay charged unless you have aftermarket large accessories. We arent in 1950 bud im sure google sais alot of things but thats false info.
hamburgernet@reddit
The alternator will maintain
Kind-Pop-7205@reddit
The car should be fully outdoors (not in a parking structure, not in a carport), and your car should have no exhaust leaks, to start with, for this to be safe.
Kind-Pop-7205@reddit
Car running (engine idling) for extended periods of time won't drain the battery unless you have a problem with the charging circuit or battery. You are going to dillute your oil with fuel and wear out the engine prematurely if you make this habitual though.
Guilty_Anything7606@reddit (OP)
i don’t get why this is even downvoted. people truly downvote just to downvote.
motorcycleryder74@reddit
Co2 only kills some people.
acadburn2@reddit
Only if hes inside with a garage door closed, and the room has no venting
motorcycleryder74@reddit
No actually being in a car, running, they can leak enough co2 into the cabin to KILL you without being in a garage.
Occams_RZR900@reddit
Maybe if you have some rust bucket POS with a busted up exhaust. I’ve spent several 10 hour shifts when I was a cop on slow nights sitting in my car parked while idling.
photojournalistus@reddit
I witnessed two Chicago cops sleep in their car all night with the engine running.
Occams_RZR900@reddit
I’m not surprised. Prior to our union fighting for a “safety clause” regarding how many hours we could be on duty for, it wasn’t uncommon for a graveyard guy who worked 6p-4a to work a shift, have to be in court at 8am, which usually lasted all day so you’d finish court at 5pm and then have to start your next shift at 6pm. If the shift was at minimum staffing levels you couldn’t take the night off, so you’d be awake sometimes for 36+ hours. Yeah, it was definitely a thing where you’d meet up in somewhere like a church parking lot with a buddy and go car to car so you could take a nap while they watched your back.
Big-Pickle5893@reddit
Did you glaze their car like a doughnut?
Lyo-lyok_student@reddit
I have no idea how you guys do that!
VisserThirtyFour@reddit
Usually involves sitting
Guilty_Anything7606@reddit (OP)
👀
how probable is this? i often sit in my car for an hr or 2 with the ac and car running. sometimes ill turn the ac off but the car will still be running.
Tangboy50000@reddit
Idling with the AC running for extended periods of time can lead to a vehicle fire if your cooling system is basically older. Maybe you haven’t checked or changed the coolant in awhile, and the fans have to work overtime trying to cool the engine down. Eventually a wire melts and catches fire, and the car is quickly engulfed in flames. If you’re sleeping, that’s not going to end well.
Embarrassed-Age6542@reddit
As long as you are awake, no problem. However there have been situations where the vehicle is parked in something like a snowdrift ( the muffler has restricted flow ) and the occupants start to feel sleepy. Fade to black.
Guilty_Anything7606@reddit (OP)
sadly it doesn’t snow here. just hot humid and nasty.
i hear it happen a lot and ive been so paranoid ever since hearing about it lol. i think ill make a post dedicated to this topic and everyone can argue until theres a general consensus of what, how, and when will it happen.
hoodedrobin1@reddit
Buy a battery operated co2 detector. You’ll be fine. Stay vigilant of your surroundings. Chick life is hard mode.
Guilty_Anything7606@reddit (OP)
I’m going to buy that when i have the money for it. Will def help with the paranoia.
I went back home sadly. I’m just going to stone wall my family. I wish it was winter so I could’ve just stayed out with my car.
frysonlypairofpants@reddit
Carbon monoxide is a heavier than air toxic gas, but cars aren't airtight, if you have outside air being pushed in from the fan, it will cause any CO that makes it into the cabin to flow out through gaps. Continued exposure even at low levels can lead to blood toxicity though because it takes a while to get out of the blood stream.
You can get CO detectors that are USB chargeable for about $100.
Guilty_Anything7606@reddit (OP)
Is there any way to avoid this even happening to begin with? Like does it have to do with what circulation the ac is on or something?
frysonlypairofpants@reddit
Gas molecules are tiny, you'd need lab-grade equipment to make cabin air 100% clean, even though the actual risk is quite low the consequences for not being absolutely certain are very bad. Just like lead or mercury, there are trace amounts of CO all over the place, you just need to avoid concentrations reaching toxic levels.
You can always start with the meter, and then make an informed decision if some kind of ventilation solution is necessary or not.
Guilty_Anything7606@reddit (OP)
Yeah tbh when I make enough money, I’ll probably get one. I’ve been paranoid about this since I first heard about it. Getting one would definitely help with that paranoia. I lowkey smell a light gas smell so may go inside my home sadly.
TrifleImpossible5997@reddit
Actually thanks to catalytic converters, it's pretty hard even in a garage. Unless your cat was stolen or your car was manufactured in the 1970's
PlatypusDependent271@reddit
Beat me to it
Guilty_Anything7606@reddit (OP)
i’m a girl
daybaek@reddit
nah it's prolly not safe then
Guilty_Anything7606@reddit (OP)
🤣 i was just correcting him. i found it funny that he thought a guy would have a pink avatar wearing a bunny suit.
JakeD51@reddit
I know multiple men that would do that lol
Guilty_Anything7606@reddit (OP)
even with “princess🐈⬛🎀” in their bio?😭
JakeD51@reddit
I mean gay guys and nobody is clicking profiles they are replying to lol
Guilty_Anything7606@reddit (OP)
True true.
TrifleImpossible5997@reddit
Not in my neighborhood.
Apparently not at MIT either
OpticalDelusion@reddit
Did you read the headline or a news article when you were 15 and never think about it again? Cuz it is mostly safe, and you provided zero of the reasons it wouldn't be
motorcycleryder74@reddit
There is a cabin air filter that lets in gasses that you are not supposed to breathe. Fuck off faggot.
millernerd@reddit
CO, not CO2
(CO doesn't hurt to breath like CO2 does)
motorcycleryder74@reddit
Correct my bad
Funautotechnician1@reddit
What kind of car?
Flimsy-Penalty6474@reddit
Paramedic here. It’s generally safe. But one exhaust leak could mean death from Carbon Monoxide. Get yourself a carbon monoxide detector. They are cheap and worth it.
wdean13@reddit
only if you drive an E.V.
Stock-Swing-797@reddit
Fell asleep while charging a Cadillac Vistiq once on a hot Florida summer night. Not sure of the exact duration, but woke up to it being like 55°F inside, sooooo nice lmao.
Ashkill115@reddit
If your in a closed space carbon monoxide poisoning is a big problem because of exhaust fumes from the engine but if your in an open space then its no problem. Though long idle hours is not good on the engine due to carbon buildup inside the engine. All engines are designed literally to be driven over 3k rpm for most of its life usually.
saskyfarmboy@reddit
Not sure what kind of vehicles you're driving but I drive over 100,000km/year across multiple vehicles and if any of them was running at more than 3,000 rpm for anything other than rapid, aggressive acceleration I would immediately pull over and shut it off.
Both my gas and my diesel vehicles rarely break 2,000 rpm during normal use.
Ashkill115@reddit
True it depends on what you drive. I’m used to driving vehicles with shorter gear ratios on both automatic and manual so I was basing it off what I’ve driven
pixel_loupe@reddit
Lots of smaller cars are above 3k rpm at highway speeds . 7th gen Honda civic, Toyota GR86, Nissan versa etc
TrifleImpossible5997@reddit
If your car doesn't have a catalytic converter, like they all basically do since 1995
SuperIga@reddit
What? Carbon monoxide poisoning from running a car in an enclosed space is of equal concern whether it has a catalytic converter or not. No clue where you’re getting this from.
Guilty_Anything7606@reddit (OP)
I’ll just see if i can sleep over someone’s house. I don’t want to go back home and I don’t want to damage my car.
Plane_Translator2008@reddit
This is really the best idea.
Guilty_Anything7606@reddit (OP)
Can’t go to anyone else’s house so i’m just going to stay in my car until my family hopefully fall asleep so i can go in and not see them.
Ashkill115@reddit
It won’t destroy it, you’ll just add more wear on it. You’ll have to replace the engine oil sooner than usual and keep an eye on the air filter and whatnot. But when you do drive it then at least redline it a few times as it can help reduce carbon buildup if your not afraid of a little noise
MarkVII88@reddit
No, not really safe and definitely not smart.
Low-Confusion822@reddit
It should be fine but if you're going to start doing these long idle periods often, might wanna step up the preventative maintenance. Is it a gdi engine? Valve cleaning. Coolant flush, fluid exchanges. Is there a recommended time or mileage limit for the water pump/timing belt? Are any of the components plastic; coolant elbows, fittings, fittings,etc? Keep the oil changed. Short trips are actually killer on engines and fluids. Any water accumulation in the oil, brake fluid, power steering fluid, trans fluid, etc never has the chance to fully burn off. If you ever pop an oil cap off an engine and see a slight white film, this could be (besides a blown head gasket) directly caused by short trips. The contaminants now degrade it, potentially increasing friction and premature engine wear. And if it's a fully synthetic oil you use, definitely dont do 10k mile intervals. Due to the way most engines operate, by 7k that oil is heavily diluted by fuel. Which can again, increase friction/wear, shortening the life of an engine.
AlphaDisconnect@reddit
It as safe as you make it.
The_Summary_Man_713@reddit
I car camp a lot in my 4Runner and I’m actually about to do it on Friday in Utah somewhere. I would not leave your car on and just suck it up. Go to Walmart and get a chargeable or battery power fan that you can put in the vehicle to sleep in. It’s just not worth it to sleep with the engine on. On top of that, if you are in an enclosed space, you will get carbon monoxide poisoning.
Guilty_Anything7606@reddit (OP)
I was always curious about the carbon monoxide poisoning. Glad to know it’s only in enclosed places. I do often car rot when I get home.
Everywhere closes in 10 minutes. Won’t have the time.
NickDandy@reddit
Just a reminder, the interior of your car is an enclosed space.
oldmanelements@reddit
thats not what they mean by an enclosed space.. are you really that daft?
HugsDrugsShrugs@reddit
Had a coworker die a couple months back because exhaust leak into the cab.
It's pretty enclosed
Guilty_Anything7606@reddit (OP)
So it could still happen? What if i leave the ac off or on? How exactly does it get released? Like if the car was off would it get released? If it’s only half way on and not engine running will it happen?
secderpsi@reddit
It could still happen even if your car is in an open parking lot. The chance of it happening depends on the type of car you drive, the condition of the car, and how much wind is present. My step dad's old car was didn't look in too bad shape, but it wasn't well sealed and exhaust would absolutely get inside if he idled still. If you have a brand new luxury car that has an idling pet mode, then that may be an example of a car that's relatively safe to fall asleep while running. In any case, it's not worth the risk IMO. Even if it's low, its an avoidable risk. Don't die from an avoidable risk.
ShadowAdam@reddit
I'm sure you've already gotten your answer, but it's probably not great for the health of the vehicle, though falling asleep in 90+ degree weather would probably be worse for you.
I did wanna say a couple quick things just for your own knowledge
You aren't worried about the level of oil per say when you change it, you are worried about the small volume of additives in the oil which help preserve the life of the engine. When these have left the oil or been broken down you won't see a decrease in a volume of oil, but a decrease in a quality of oil. You cannot eyeball the quality of oil in a decent car, you need lab testing. That being said if you don't drive much it's probably fine. Personally for a decent car I'd say 7500 miles is the cut off, if you aren't too hard on it
You didn't have a cylinder replaced, at least, not one if the main cylinders that people think of. Those aren't something you just replace, you'd need a whole new block. You might have had a piston (though that's not really a "we have only fixed" part, pretty intensive and severe) replaced or the coil pack? I'm just saying I'd try and figure out what that part was for your own info/to make sure the shop didn't scam you
OneEyedDoofus@reddit
It will not affect your battery, the alternator will keep charge as long as the vehicle is running. Idle hours are a killer tho hence why cop cars are sold so early and for so cheap. I recommend pumping the coldest AC you can get before sleeping, then your body will wake you up when it’s too hot. At that point turn the car on to warm up, step out to smoke or stretch, then pump more cold AC, obviously shutting it off again before sleeping. That’s what I did with the about month and a half I was homeless. But be careful, I lost almost 30 pounds in that short time and I was eating more then than I am with a home
JankyTime1@reddit
I've done it many times. Hot shot truckers do it every day. Just crack a window and if worried about it get a battery or 12v powered CO alarm. The ones made for boats are all 12v.
MatiasGonzalo-Duarte@reddit
Underrated EV perk tbh
Can sit with the AC or heat for hours and hours no wear and tear to the engine to worry about with idling
Guilty_Anything7606@reddit (OP)
Do they have the same co2 poisoning risk?
MatiasGonzalo-Duarte@reddit
No, there's nothing burning in an EV.
Guilty_Anything7606@reddit (OP)
intriguing. though i’m sure it still has its own issue being fully electronic. especially teslas with them always blowing up.
friendIdiglove@reddit
Your car will be fine. I hope you will be too.
Hybrids are ideal for that use (better than EVs as far as I’m concerned), but at the same time, you don’t need a permanent solution to a hopefully temporary problem.
Guilty_Anything7606@reddit (OP)
Thanks. I went back home like 30 mins ago. I’m playing the ignoring game. I called a family friend to come deal (as in lecture lol) with my family tomorrow, because I honestly can’t anymore.
I mentioned in the edit electric cars just aren’t sustainable where I live at all. Literally today we haven’t had power since 5 and it won’t come on until later today. Now imagine having to evacuate and your damn car battery is dead and you can’t charge it lol. It’s just not good at all.
Some of my family members in cali have electric cars. Now having an electric car there is reliable and much more sustainable with their crazy gas prices.
Yeah a lot of people were talking about buying a car for this lol. In their defense I don’t think I mentioned it being a one time thing in my post. They probs thought my only choice was to live in a car from now on.
fonacionsrg@reddit
Sleeping in a running car for hours in heat can be risky for both safety and mechanical strain. If possible, a shaded spot or safer cooling option would be more reliable for that time window.
Guilty_Anything7606@reddit (OP)
i went back home. time to play the ignoring game.
Ok_Alternative7120@reddit
It is perfectly fine. I sleep in my car on long road trips from time to time. Just don't do it in enclosed spaces. I park at a rest stop, truck stop, commuter lot, etc and sleep for a few hours then finish the drive. You are not putting enough time in it to damage your car. It's tens of thousands of hours of idling before you typically actually cause damage to your car. Sleeping in it while it runs for 5 hours here or there is not going to hurt it. Just make sure your fans are working well in it since you mentioned temps being hot there. If your fans are fine, you'll be fine. If you have a bad fan, you can overheat the car. But if your car is in decent shape, just sleep in it tonight. It's perfectly fine. Don't let people scare you lol. Semi drivers do it all the time. First responders and military vehicles are constantly idling and being operated by complete buffoons and still last years under the abuse. Don't worry.
guffy-11@reddit
Coast to coast AM!?
Guilty_Anything7606@reddit (OP)
thanks! i decided not to do it. i am however going to wait in my car for a few hours and go inside. hopefully my family will be asleep by then. i don’t want to see them.
mckenzie_keith@reddit
The only danger is the carbon monoxide in the exhaust. If you have an exhaust leak you may never wake up! Or if you do it in an enclosed space like a garage or a car port, then it would be very dangerous. If it is wide open around you, and you are not in a crowded parking lot full of idling vehicles, it should be safe.
Hitt1te@reddit
Nope. At least get a Carbon monoxide alarm. Best thing is to get a hybrid or a remote starter where you can turn it on or off while laying down.
AbzoluteZ3RO@reddit
I've done it many many many times. It's perfectly safe as long as you aren't in an enclosed garage and you don't have any weird exhaust leaks under your car
GraveDanger884@reddit
Its fine. Just make sure you have adequate ventilation. Ive spent countless nights in a work truck asleep with the ac or heat on. My personal truck has ran overnight dozens of times. My well used police car has 11.5k idle hours on it. I hope your situation improves
SufficientThroat1181@reddit
Nothing will happen. A lot of guys saying there will be wear and tear in your engine, it wont. Leave little crack on your window and AC on when you sleep. I have left the car running thousands of hours idling nothing ever happens. Make sure you got gas.
PlasticTreeonaHill@reddit
No
Guilty_Anything7606@reddit (OP)
thank you for the detailed response
nyrb001@reddit
It won't instantly damage anything, but idling an engine for an hour is similar to driving 60-100 miles. So idling it from 10pm to 8am is like driving 600-1000 miles in terms of wear.
Not a big deal for a night or two, but if you plan on doing it every night for weeks and weeks, you're adding serious hours to your engine.
Guilty_Anything7606@reddit (OP)
This happens in only an hr????!! I car rot very often for like an hr or 2 like everyday.😳
BisexualCaveman@reddit
The established number in fleet management is 30 miles per hour worth of wear from idling.
33 if you listen to Ford.
I wouldn't worry about it.
Strange_Produce5601@reddit
no, this is completely made up numbers. Otherwise taxis, busses, semi-trucks and many other engines would be granading left and right.
nyrb001@reddit
Change your oil more often, change your air filter more often, make sure your cooling system is working well.
Cars are designed to be used - you aren't going to instantly break it or anything as long as it isn't overheating.
The cars you see hitting super high mileage are generally ones that are running on the highway all day - lots of miles per hour of runtime. Whereas cars driven in the city a lot don't always last as long because they have lots of hours of runtime despite not having as many miles.
Mizar97@reddit
If you leave the accessories on but not the engine, it will 100% kill the battery. AC also doesn't work unless the engine is running.
You don't do a ton of damage by letting it idle all night but you'll use several gallons of gas.
CaptainMischievous@reddit
I had to spend the night in a van in single digit weather once and you can bet I left the motor idling. I was careful to point the tailpipe downwind (and it was windy that night) of the engine to minimize CO infiltration. Was glad to see the sunrise next day and continue on my way. Put another 100K miles on that engine. Still running fine when traded in at about 320K.
l008com@reddit
No. You're going to burn probably a whole tank of gas, or close to it. And for nothing? Plus its bad for the engine to idle for super long periods like that.
gotcha640@reddit
I’ve slept in my car plenty of times with the engine running. Houston in the summer, over 100f, park under any kind of shade and curl up in the back for 6 hours. 2013 Suburban was at 180k miles when I sold it. Oil changes at 5k.
It’s fine.
The car will be quieter and private, a couch is usually more comfortable and closer to a bathroom.
Guilty_Anything7606@reddit (OP)
with the ac on or off? i also live in the south. unless it was winter, i’d NEVER sleep with the windows open. the roaches and the termites would surely get in.
gotcha640@reddit
AC on when I’m in it. AC was off when we were using it as a generator for the fridge.
Melodic-Classic391@reddit
Is this a beater or a nice, well maintained car? Where will you be parked? I wouldn’t do this if I had an older car with potential exhaust leaks and obviously not in a closed space.
Guilty_Anything7606@reddit (OP)
mazda cx5 2015. i maintain the car well and so did the previous owners (supposedly). i did have to change the spark plug and one of the cylinders when i first got it though.
GalaganCoffee@reddit
You'll need to add several oil changes per year and there's carbon build up and wear on all the bearings belts hoses.
It's like driving 30 mph the whole time, 240 miles of extra wear a night.
NotslowNSX@reddit
I saw some guys sleeping in a running car for the air conditioning (lake havisu, spring break). The guy in the driver seat was resting his foot on the pedal, just revving the crap out of the engine while sound asleep/passed out. I banged on the window and woke him up. I'm sure that car had some excessive wear from one night of running, lol.
SpaceCat72@reddit
I would not. I lived in my truck for a year in West texas. It was hot as hell and a bit cold at times I couldn't trust something bad not to happen. Left all windows cracked about 2 inches
BFCE@reddit
It'll be fine. Like everyone else says, change your oil more frequently. I'd recommend keeping an eye on coolant temps too.
South-Range8401@reddit
It will damage your engine, not horrible right away but it will shave years off the life of it
Guilty_Anything7606@reddit (OP)
Damn can’t afford that.
South-Range8401@reddit
The reason is because the engine is designed to have air flowing through it to perform optimally. When it doesn't have airflow, lots of byproducts have nowhere to go, they gum up valves and crevices. When youre driving everything is flowing through the exhaust properly
Heavy_Gap_5047@reddit
Gum in crevices, hmmmmm
South-Range8401@reddit
I mean it's just my opinion. I was trying to explain it simply. Idk why I even comment on posts like this. Cars aren't meant to idle for 5 fucking hours. But go ahead and idle your car I really could care less
Heavy_Gap_5047@reddit
https://www.youtube.com/watch?v=8Gv0H-vPoDc
South-Range8401@reddit
I wish I never commented on this post
Heavy_Gap_5047@reddit
I too wish you hadn't.
Strange_Produce5601@reddit
Oh, it seems you misunderstand how an engine works. The air is exploding constantly in the cylinders. It does not need forward motion of the vehicle to function correctly. The engine will always be drawing how much air it needs depending on its load. So at idle, it does not need much air to function correctly. I assure you, the byproducts are being flushed through the exhaust regardless of how fast you are going.
Strange_Produce5601@reddit
it will not shave "years" of life off your engine. It will just mean you have to do an oil change sooner if you let it idle lots.
NothingSuss1@reddit
Police, security guards, taxi drivers etc all would be trashing engines weekly if it were that serious lol.
Kennylobster8899@reddit
I've heard of a couple teenagers who died in their truck while it was idling OUTSIDE but because it had a small exhaust leak underneath
181513@reddit
Tesla Model 3 or Model Y has camp mode. Model Y is comfortable to sleep in and uses about 10% for 8 hours.
Heavy_Gap_5047@reddit
Wow there's a lot of stupid in these replies.
Here4discountCompTIA@reddit
I’ve accidentally left my car on all night from 7 pm to 7 am. That was 7 years ago and my car is still doing fine. Also left it on from 1-7 am when I went camping because it was so cold.
u_siciliano@reddit
Just adding my 2 cents. Carbon Monoxide getting in your sleeping quarters is always possible if exhaust leaks, cabin has a breach or a low wind blowing exhaust back under car. Sleeping that long is a risk, no matter how small. Just my opinion.
Aaronator20@reddit
Carbon monoxide poisoning
Guilty_Anything7606@reddit (OP)
is that with the ac on or off?
Barfy_McBarf_Face@reddit
carbon monoxide will possibly build up if you're in a garage or other enclosed space, if there's poor air circulation, or if you have a leak in your exhaust system. Nothing to do with whether your A/C is on or off, it's a combustion byproduct. It's clear, odorless, and extremely dangerous - you keep breathing, but it bonds with the hemoglobin in your blood, preventing oxygen from being bonded & carried to your cells. You just ... pass out and die.
so if you have a leaky exhaust system, or you're in an enclosed area, this is a bad idea.
Guilty_Anything7606@reddit (OP)
But not a bad idea if i’m in an open parking lot?
Barfy_McBarf_Face@reddit
again, it may be hard on your engine, but if your exhaust system is good, it may be ok
there are better ways to do this - the fan idea is a good one. And less burning of fuel while you do this. A running car engine isn't a quiet thing, and it's polluting while you're sleeping.
Aaronator20@reddit
It's from the engine running bro
Guilty_Anything7606@reddit (OP)
idk man i’m just a girl fr. at least now ik the real cause is if you’re parked in an enclosed place.
Strange_Produce5601@reddit
AC is irrelevant here. It will only poison you if there is an exhaust leak letting exhaust fumes directly into the cabin. Or you are in a confined space, like a garage.
Guilty_Anything7606@reddit (OP)
thanks!
JSTootell@reddit
The engine produces CO, which is very deadly. But it's only an issue in an enclosed area.
If you are parked outside, you will be fine.
Guilty_Anything7606@reddit (OP)
okay thanks!
geoabitrage@reddit
ICE engine will be cooked. You will definitely need a new car after leaving the one you have now running all night. That's absurd and abuse of a working engine. Why don't you just get an EV car like Tesla used. You can let the AC at set temperature all night
Guilty_Anything7606@reddit (OP)
Ugly electric cars aren’t sustainable where I live. We don’t have charging stations, only gas stations. We also have constant power outages, so that will be even worse. All around would be a horrible idea to own one here.
geoabitrage@reddit
Ugly EV cars? You have been living under a rock? Unless you're referring to Elon's vehicles.
geoabitrage@reddit
If you're in an cold ❄️ climate, it's not doable. I live in Nevada and summer is 120 degrees, it's not a problem for me. I don't park under the sun , we have many casinos with parking garages. Why not get a Chevrolet Express cargo van? Air vent, solar panels with 200ah lithium phosphate battery x2. That would be plenty of juice. Insulate walls and floor.
Guilty_Anything7606@reddit (OP)
This is just a one time thing.
geoabitrage@reddit
Oic. I have been doing this for years. I will never ever rent or have a mortgage again. It's like winning a jackpot each year with the money I have saved.
Minimum-Reward3264@reddit
Diesel ?
Guilty_Anything7606@reddit (OP)
no gasoline
PK808370@reddit
So. It seems like you are in a parking lot, outside. It’s hot and you want the AC on.
If it’s a one-night thing, do it. You’re fine and it won’t hurt anything.
Make sure you are in a safe place to be parked.
Guilty_Anything7606@reddit (OP)
Eh should be safe enough. It’s a parking lot shopping area outside my neighborhood. Like literally connected to it.
glasswings363@reddit
Air conditioning won't run without the engine (or high-voltage system). If you're burning gasoline it's safe in a well ventilated area but expensive.
Diesel and gas-hybrid do better, battery-electric is the best.
Guilty_Anything7606@reddit (OP)
Yeah i’ll be burning gasoline. I have 144 left in my tank.
GeriatricSquid@reddit
You’ll put a lot of wear on the engine idling that long but the main safety issue is carbon monoxide poisoning if you have an exhaust leak. If the CO leaks into the car you could die in your sleep and never know it was happening.
JSTootell@reddit
If you are on a garage? No, absolutely not.
Out "camping", yes.
Not great for the engine, but you gotta do what you gotta do.
Guilty_Anything7606@reddit (OP)
i’m parked in a parking lot. how badly will it damage the engine?
JSTootell@reddit
Just adds extra wear. Look in your owners manual under "severe duty". Usually it would recommend changing the oil in a shorter interval time.
Guilty_Anything7606@reddit (OP)
i do need to change my oil soon anyways. Probs in another month.
Strange_Produce5601@reddit
it wont. Vehicles up north run non stop due to the cold.
Guilty_Anything7606@reddit (OP)
I’m in the south so it gets pretty hot like 90+. Not sure if the weather correlates at all.
Strange_Produce5601@reddit
it does not. so long as the car is not overheating.
Myke_Dubs@reddit
It is not safe and it’s very bad for the car, you can get a rechargeable fan and crack the windows for some air circulation
Barfy_McBarf_Face@reddit
yes, get a rechargeable fan that will run for at least 6 hours if not longer, and recharge it during the day from either a wall outlet or from the running car while you're driving
Guilty_Anything7606@reddit (OP)
I’m scared of cockroaches lol. Otherwise I would’ve just cracked the windows.
Feisty_Count_4409@reddit
On like running or just accessory power? Both are bad ideas for different reasons
Guilty_Anything7606@reddit (OP)
How so? What way would it not damage it by keeping the car on (on all the way).