I left my car running for 6 hours by accident, is that bad?

Ford Models Forum Ford Focus Club
1

So, I did something pretty dumb… It’s -40°C here, and my car’s battery died a few days ago, so I thought I’d start it to make sure it was still good. I went upstairs thinking I’d let it warm up for 15-20 minutes but totally forgot it was running for 6 hours. The engine temp was fine, and I only used a couple liters of gas. Everything seems fine with the car, but could this cause damage that I might have to pay for soon?

I know, I should’ve set an alarm or something. I guess I learned my lesson the hard way.

2

Don’t worry, your car should be just fine.

3

Angel said:
Don’t worry, your car should be just fine.

Phew! Glad to hear that.

4

Summer said:

Angel said:
Don’t worry, your car should be just fine.

Phew! Glad to hear that.

Car engines are tested by running at redline for 24 hours, so 6 hours of idling isn’t a big deal.

5

Summer said:

Angel said:
Don’t worry, your car should be just fine.

Phew! Glad to hear that.

I had an issue with water in my gas once, ran my car for two days straight to burn off the fuel. It only used a quarter tank, but it still worked fine. Just a little carbon buildup, but nothing a bit of injector cleaner couldn’t fix.

6

If your car can cruise at 2500rpm for hours, idling at 700rpm for 6 hours is nothing. You just wasted some gas.

7

Rowan said:
If your car can cruise at 2500rpm for hours, idling at 700rpm for 6 hours is nothing. You just wasted some gas.

I tell people that all the time when they’re stressing about their car idling for too long. It’s really not a big deal.

8

I’ve done that a few times with my 2003 Sonata when I worked graveyard shifts. I’d park for a quick nap and wake up hours later.

9

Riley said:
I’ve done that a few times with my 2003 Sonata when I worked graveyard shifts. I’d park for a quick nap and wake up hours later.

Did you sleep through most of your shift?

10

@Daniel
Haha, no! I would stop halfway through my commute since I was too tired to drive all the way. It was a long drive on backroads. I would often wake up and see kids going to school while I was just finishing my nap.

11

@Riley
Sounds like you secretly like watching kids, huh?

12

@Daniel
:joy: I’m pretty sure that’s what he meant.

13

You might want to consider changing your oil now. You’ve probably used more oil than the odometer says because of the idling.

14

At -40°C, you might have to worry about the exhaust freezing up, which can lead to corrosion. The engine didn’t get hot enough to evaporate all the water.

15

Why do people think it’s bad to let an engine idle for a bit? It happens all the time.

16

A one-time 6-hour idle isn’t going to cause any damage. You should see what cop cars go through—they idle for hours every day and still run fine.

17

Cops idle their cars for thousands of hours, so you’ll be fine. It’s just a few hours, nothing too bad.

18

You’re good. All that happens from a lot of idling is burning more gas and possibly wearing out spark plugs a bit faster. But those last a long time (80k-100k miles), so no worries.

19

Don’t stress, your car is fine.

20

My wife left her new Ford Escape idling for 9 hours once, and it didn’t hurt the car at all. It’s okay to be a bit forgetful sometimes.