Fueling While Running

[Kirk_B]

This is my first diesel truck which makes me grin every time I drive it. This site is full of awesome information! I havent seen anyone ask the question if it is ok to fuel my truck while running. I hate to shut it off while it just trying to warm up when its cold. But maybe that is the safest thing to do? The fuel cap states the engine light might come on if the cap is loose... so if I am filling it while running is that a bad thing? I am thinking it would just drop the fuel pressure a bit . . but since its just idling I dont think it would hurt anything. Please correct me if I am wrong. Thanks all!

 

[XcumminsX]

i hate turning my truck off when getting gas because i sit there and wait a minute for the truck too cool down. Then i start it up when its hot... i know thats not good for the starter. . *right?



Nick

 

[Kirk_B]

Right XcumminsX I forgot to add its a pain to do the "cool-down"-"warm-up" cycle again.

 

[SRadke]

I fuel mine while running whenever I get a chance. Round here they have people to pump your fuel for you and they won't fill it till you shut it off.



-Scott

 

[Vaughn MacKenzie]

Well luckily I don't live in that goofy state to the south of me that won't let you fuel your own rig so I always fill up without shutting off



Just givin' ya a hard time SRadke, Oregon's a great state



Vaughn

 

[CLAYTON]

I always fill up without shutting off.

 

[LEerkes]

Shut it off or let it idle?

I'd be curious to hear some of you expand on this a little and give me your opinions on idle time.



I've read several times that letting the truck idle for long periods is generally "bad". I seem to remember hearing tall tales about long haulers who hadn't shut their rigs down in years. Jut let them run all the time because it was "bad" to start them.



So, given a theft free environment. Obviously checking the mail at the mail box is a "let it idle" event and going to bed in a hotel room is a "shut it off" event. Where is the cutoff in your heads? 30 seconds, 1 minute, 3 minutes, 5, 10?



Where is the point when idling does more damage than starting?

 

[David Muench]

I never shut mine off while fueling. A gas vehicle however, I always shut off (of course).

 

[XcumminsX]

ususally takes me 4 minutes to fill my tank from empty to full... tank is getting low today i will fill it while running hopefully the gas station owner wont come outside with a gun and tell me to turn it off...



Nick

 

[NC_Mog]

I typically keep mine running, unless I have to go in the store and get something. A fuel stop of less than 10 minutes doesn't count as an extended idle.



The issue as I understand it with respect to extended idle periods has to do with the engine cooling down and not getting complete combustion. The diesel can wet the walls of the cylinders and that's the start of the problems. If you could do a fast idle to keep cylinder temps up, then the problem would go away.

 

[DLGonzo]

I aways leave mine runningn when I fill up. Even if I have to go in to pay I do. I keep an extra key in my pocket, so I just lock it up and go.



I don't know so much about the extended idle. I've just order one of the solenoids, but I've let mine idle all night before because I was sleeping in it and it was 35 degrees out side. I do change my oil very regularly.



I will have the solenoid installed as soon as I get it though.

 

[rbattelle]

I never idle while fueling. Mostly from habit. After all the time I owned gassers, it just seems wrong to leave it running while I fuel. Besides, I always check the fluids when I fuel, and you can't do that while it's running.

 

[nickleinonen]

i've never shut down any diesel engine powered vehicle that i've been fueling. now, i'll shut down gas engine vehicles, cause the exhaust makes me nausious and gasoline it self smell horrable too so i try as little as possable to fuel gasoline vehicles

 

[XcumminsX]

OK well im back from the gas station filled it up while running... All went good... I did put in 50 bucks though



Nick

 

[Kirk_B]

Thanks for all the great responses! I'll just let it run

 

[klenger]

The only time I leave it running when fueling is if I have been towing and the engine is really hot. Otherwise, I always shut it down. There is certainly no reason to wait for the engine to warm up after fueling if it was warmed up before you fueled it. They don't cool down that quickly.

 

[KKlepfer]

Letting your engine run/idle when it is warm won't hurt as long its not for an extended period of time. The reason for letting a diesel idle while fueling is that its not inherently dangerous like gas. Gas is highly flammable and diesel is just combustible. This mean that the flash point is above 100 F.



The starter on a diesel is much more expensive to replace than a gasser so the logic is if you start your engine less you'll have to replace less. I don't think this is much the issue for late model diesels because they turn over pretty efficiently these days.



I run it while fueling just because I think its cool to make alot of noise while at the station. Its more about testosterone than anything else. By the way you check your transmission fluid with the engine running and in Neutral so thats one fluid you can't check with the engine off. I idle my truck with the emergency brake on and the transmission in Neutral because the fluid circulates in N not in Park. There's a whole thread discussing this unique quality of the 48RE auto transmission.

 

[ttreibel]

Unless you take a real long time fueling you can't check the oil when your at the pump. If you don't wait 15 minutes for the oil drain back you will over-fill up to 2 quarts been there done that.



The only negative of leaving the truck running is the minute chance of race-away from excesive gas vapors in the area but if you smelled vapors that strong your best bet is keep on driving before tragedy strikes.

 

[KKlepfer]

Where is the point when idling does more damage than starting?

I seem to remember a thread that stated idling your diesel when cold is bad period. Our engines run so efficiently that idling doesn't warm them up in cold weather. A cold engine idling doesn't adequately burn the fuel during the compression cycle so there is the possibility of oil dilution as a result.



When your engine is hot/operating temp, I remember the magic time of 15 or 20 minutes and I don't know why... its just what I remember reading in one of the threads here on TDR.

 

[Belchos]

To Radke in Oregon: Oregon law allows you to fuel your own vehicle with diesel. The rationale for the law is safety, and the diesel is inherently safe in fueling. However, it is not worth having to argue about it with all the zit-faced little buttheads who work in Oregon stations, especially at night. I get into this all the time because of fueling-my-own habit I developed in California.