Can I idle my Tahoe for 8+ hours once without damaging the vehicle?

Ok, I’m going to run an ultramarathon down in the Everglades. There isn’t anywhere to shack up for the night within an hour of the race start. There will be camping allowed near the start, but I’m a pretty light sleeper and also have a very hard time sleeping in potentially warm/humid weather. I’m thinking about sleeping in the back of my Tahoe, which I could handle, but I’m wondering if I could idle the thing safely overnight for the AC. It wouldn’t run through a full tank of gas at idle for that long (I think) but is there any danger to the engine etc… from idling that long?

It’s not ideal I know and I would never consider this at any other time but camping in a tent probably won’t work for me.


I have known people that have idled vehicles that long before for and nothing long-term happened. Or rather, nothing down the road that could be attributed to them doing that happened. Though, they did not have A/C running, it was in the winter and they needed heat.

Your alternator does not really make any power until at highway RPMs so you might drain your battery over night as the some A/C components might require DC, the radiator fans will be going on (probably 1/2 the time), plus the cabin blower motor, and anything else.

I’d have a portable battery booster pack to be safe.

Borrow a diesel one from somebody you know??

My alternator will carry everything going at once at 25 MPH. Just a bit above Idle. You can up that your self.

I would do a test at home before driving all that way.
That will check the fuel usage also.

YMMV :smiley:

How hot is the temperature supposed to be that night (or the historical average)? At nighttime it could well be cool enough (for me the vibration and noise of the engine running would probably bother me).

Brings back a bit of a memory…Being rather curious a few (40+) years ago, I filled the tank of my 59 Biscayne and let it run to see how long it would run. At idle. It actually quit after about 9 hours with about 2/3 of a tank left. I hadn’t realized how fast the plugs would foul, as this car at that time went through a quart of oil every hundred miles or so. But by extrapolation it would have run over a day. No harm otherwise, didn’t even heat up.

Can’t think of any reason why idling that long should cause a problem. I guess overheating would be the most likely problem, especially if you were running the air con.

Make sure your catalytic convertor isn’t over grass or anything flammable. And you’d probably want to make sure that you’re far from other sleepers.

It’s not going to hurt it, the only dangers (to you or the car) are running out of gas and CO leaking into the cab.

Yeah, I wouldn’t do it due to the possibility of carbon monoxide poisoning. What’s wrong with being too warm? I dream of being too warm at this point in winter.

I can think of a few ways to deal with that, but if this is a campsite type situation, I’d be worried about people walking around an night and burning themselves.
But my thoughts are to go to an auto parts store and and get a 4 or 5 foot section of exhaust pipe that you can slip over your exhaust pipe to take it away from the car. Either get an elbow so it goes up (and find a way to temporarily mount it) or go straight back and just get someone to weld and A-Frame to it somewhere so it’s propped up.

Again, these are issues if people are going to be walking around, but if there’s no one nearby that’s what I’d at least think about. The problem is, if there’s no wind, the exhaust could accumulate under the truck and find it’s way in. This system might not be perfect, but if it can at least get most of the exhaust a few feet away, that’s going to be helpful.

I accidentally left my Honda Oddysey minivan idling overnight in a parking ramp while on a trip in Iowa, more than 10 years ago.:smack:

Still running fine now. Me, I’m still getting over my chagrin.

you could start a grass fire with a hot exhaust system.

drive a bit before parking at the campsite. set the AC to Eskimo, when parked don’t open doors or windows, the car should stay cool for a couple hours. if you wake then take another drive with the AC.

I’ve left my car idling all day while I was at work… twice… Stupid electronic keys.

So enjoy!

Not really true anymore. Pretty much any vehicle made in the last 10-15 years have variable output alternators that are computer controlled. At idle they can supply the needed power to keep a stock vehicle charged pretty much indefinitely.

Right, and even when it was true, it was true for some vehicles but not others. More likely to be true for a car, less likely for a truck, in my limited experience. My Ford Aerostar could charge another car’s battery at idle without draining its own, but I remember other cars that couldn’t.


The risks of CO poisoning are too high in an idled vehicle to make this a good idea. If there is the tiniest of pinpricks in your exhaust system, you could easily allow enough CO to seep into your vehicle’s cab to make your night’s sleep a permanent one.

Get a CO detector, that will make sure you are OK, and consider others where you may be running the truck. Small chance of catastrophic engine damage as there will be no one awake to see if the oil pressure light goes on or if the car overheats.