I see No Place to write in my question. This is my first time.
My question: I accidentally left my car in Park and running for 4 hours. Did I damage my 2010 Nissan Altima?
Hi rocilladilger:
Nothing to worry about. You did no damage at all.
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The wife of a colleague of mine once left her car running for the entire night before discovering that she had failed to shut off the ignition. Aside from wasting a lot of gas, no damage was done, and engine had no problems whatsoever for the ensuing 3 years that they owned the car.
All of that being said, more people do damage to their engines by failing to regularly check the level of oil on the dipstick, and many of these same people do damage to their tires by failing to check (and correct) the inflation pressure on a regular basis. Do you do both of those things? If not, then you have much greater potential to do harm to your car by things other than allowing the engine to run at idle speed for 4 hours.
+2
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Any modern car in good operating condition can idel 'til the tank runs dry without damage… up until that point where the tank actually runs dry.
In the old days of carbureted engines, the engines idled “rich”, with a lot of unburned and poorly burned fuel. This left a lot of carbon in the cylinders and the excess fuel could even bypass the rings and dilute the oil. Leaving an engine idling for hours could result in carbon buildup and even diluted oil. But modern engines idle very lean, very clean, and don’t leave these deposits, and these are no longer concerns.
In short, fears of long term idling are a hangover from the days of carbureted engines. The reasons no longer apply.
Modern cars are also very quiet at idle so I see how this could happen, although it would be difficult to duplicate with my 2010 Kia. When I opened the door the key in ignition chime would start “dinging” and it also would not allow me to lock the door with key in ignition.
The worst thing that happened is to feel silly that it happened. No harm, no foul 
Did you do this in your garage or outside? If you did it in your garage, please make sure your house has a carbon monoxide detector in case this ever happens again.
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I’ve read about Alaskans leaving their cars running all night in the winter and while parked for long times, such as to see a sporting event. I think the more-efficient thing to do at home is hook up an engine heater.
The push button has nice functionality. When recently buying a new car, I avoided the push button because I knew my wife would forget to turn off the car about as frequent as she forgot to turn off the dome light or headlights.
When test driving cars, I tested the push button on the mazda. As you found out, they don’t turn off on their own even when the key fob is way out of distance. It is likely a safety thing but I would think if it is out of range and in park, it could safely shut off the car.
One of my coworkers has a Altima and I walked by his car in the parking lot at lunch time. I called him to let him know that his car was still running in the parking lot.
Don’t worry. You did not damage you car. It just cost you a few bucks in gas.
When I drove truck to Montreal they sometimes sent us to a mote with our tractor and the motel had no plugins. sometimes we were there 14 hours. We never shut them off in the winter.
What you’ve heard is true. Many vehicles in extreme climates are left running unless they’ll be out of service for an extended period, especially diesel engines and air cooled engines (like small aircraft). Engine heaters are great, but they don’t always “cut the mustard” in Alaska, and air cooled engines have no coolant to circulate heat. Diesels can be impossible to restart in Alaskan temperatures. It’s a different world in very extreme temperatures.
Unlikely to have causes any damage. But it does stress the engine’s electric cooling fan, so good idea to make sure that fan turns on consistently when the engine temperature gauge moves past the 1/2 way mark or so. If that fan or its temp sensor failed during the 4 hour idle, the resultant cooling system overheating could have damaged the engine. The other potential stress is if the gas tank runs to empty and the car stalls out from lack of gas, that can damage the cat.
Way back in 1962 my BIL had a 54 Desoto that needed a new starter but he couldn’t find one. So the car ran all day and all night for weeks until he fixed it. Nothing to worry about. More than once I’ve crawled home in traffic at about idle for over four hours and no harm done except needing more gas.
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The car will be fine. If you did it in your attached garage you should check on your pets and family! Run.