Let it run or turn it off?

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Units

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Have had my 2023 6.7l for 2 weeks. Curious as to what others are doing with their engines while fueling up, I see folks all the time gassing up and leaving their engine running. I know these engines use a grid heater and do not use glow plugs, does that even matter in regards to starting the truck? Maybe that’s an old school train of thought in regards to diesels. I also see where the user manual says to limit excessive idle time. The one time I’ve gassed up so far I just let it run. What does everyone else do while gassing up?
 

chri5k

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I shut down. Usually I am running inside for a drink or snack. The grid heater only runs when the engine cold so not really a consideration at a fuel stop. If you don’t do a lot of highway driving I would shut down. Stop and go as well a lots of idling can lead to emissions system issues.
 
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crash68

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Idling 5-10 minutes is fine longer than that turn it off. Unlike a gasser diesel cool off while idling, if your working the engine like when towing/hauling it's a practice to let the engine idle to cool for a few minutes before turning off. There's not as much worry about cooking turbo bearings as they're liquid cooled.
As mentioned above having a grid heater(or glow plugs) has no bearing on letting the engine idle.
 

nlambert182

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If I'm not going inside I let it run. In the 5-6 minutes that it takes to fill up it isn't going to affect anything by that much.

The grid heater is a non-issue.
 

Fuel35 67

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Diesel doesn’t ignite like gas. Pretty sure you’d be alright.
 

Gr8bawana

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There is no reason to shut it down.
 

nlambert182

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It's illegal and dangerous to leave your vehicle running when fueling. If I need to cool down the motor before shutting off, I do that in a parking lot, not at the pump.
Someone may need to tell all the truckers at the big pumps this.... I can't name a time where I've been at the trucker fuel islands without at least 2-3 diesels running while fueling.

It might be illegal (possibly due to a fire code) in some areas, but it is not illegal everywhere. I've seen a few signs at the GAS pumps mentioning to shut off your engine but I've not seen those signs at the diesel pumps.
 
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