Fueling

[Cancerman]

Since this is my first diesel vehicle to own, and have only had it since March, I have some questions on proper fueling.
When I pull into the pump at Wally Mart, I shut off my engine and proceed to fill her up. Many times a PSD will pull up to the other side of pump (no Duramax yet)and proceed to fill up. About half the time they do NOT shut off their engine.
Is this because:
1. The PSD is hard to start?
2. Nobody wants a PSD, and so it will not be stolen when they go to pay the cashier?
3. They have gone deaf from the PSD and don't realize it is still running?

Seriously, I would think that this is a safety hazard as there could be gasoline being pumped from the other side of the pump!

Well, I am sure someone can enlighten me in this area.
:D

[ChevysRus]

First welcome to the forum and may you get all the answers you seek and have many miles of carefree trucking. OK you have to explain cancerman, either you are a body shop guy who likes to work on rust or you are an Onancologist Oh hell that is probably the bird specialist LOL

Anyway, hope it's one or the other and you don't have it!!

Anyway, there is no real preference one way or the other, some people believe you have to let a diesel idle to cool down the turbo and you should never shut it off hot. So probably the guy figures it's better to let it run a few minutes rather than stop it hot and then re-start ina few minutes.

Maybe he just didn't want to shut dwn the A/C LOL
Anyway, there is no real reason to shut it down or not to shut it down while fueling. Just persoanl preference. Danger is no more or no less I suppose while fueling. Probably not the best idea, but not the worse either. I always am amazed at the guys and gals who light up the Marlboro while pumping the fuel. Bigger risk there. I suppose there is always the worse case scenerio to deal with, but what are the odds anyway.

So just fuel up and let those PSD & Dodge boys blow themselves up LOL ha ha ha

have a great day!

[Flyboy]

The only reason I would leave my Duramax running is if I had been pulling hard and needed to cool the turbo down before shutting off. Never owned a PSD so I don't know why they are left running.

[odoh]

Hmmm, good point. No ign, spark for igniting flamable (ajacent 'gas' pumps). Its not just the PSDs. I've seen tractor trailers pump while running. Difference between flamables and combustionables? Firefighter son tells of a natural gas situation where the engine was too close to the source and wouldn't shut down~ odoh

[oneton]

Ok, here's another theory. The company I work for years ago had us keep the PSD running for fear of using up the starters. I rememeber reading this wasn't a good idea because of "wet soak" condition of unburned fuel staying in the cylinder during these extended idle(ing) periods.

[SoCalDMAX]

Hahaha!

How about #4, all of the above. ;)

Regards, Steve

[Cancerman]

ChevysRus,
I took the screen name of Cancerman from the series X-Files.
Mulder's father, if you saw the last episode, Cancerman ate a rocket. (He's probably still not dead!)

When I was in Canada, they were very strict about having you shut a gas engine off before re-fueling. How about diesels? eh!

[SoCalDieselNewbie]

Personally, I think it is a Turbo cool down issue and then a starter issue.

In fact, I have been seriously considering adding an "Auto Shutdown" module to my truck.

What it does is measure the Turbo's temp and idles the truck until the Turbo's temp lowers to an acceptable temp.

So theoretically, you could turn off the ignition and pump fuel... hop back in the truck and the motor is still running because the turbo's temp is low enough yet.

I fuel while the truck running because most of my fueling is done after being in serious, Los Angeles style, rush hour traffic.

[MaxRock]

Cancerman,

"Many times a PSD will pull up to the other side of pump (no Duramax yet)and proceed to fill up."

You need to drive east on FM 121 about 20 miles and I can show you a big black Chevy Duramax! We are darn near neighbors... :D !

MaxRock

[NutNbutGMC]

^...LMAO....WFC?

[ 07-11-2002: Message edited by: NutNbutGMC ]</p>

[ford2chevy]

Unburned fuel in the cylinder only when the truck is not at operating temperature. We don't need to worry about it in the summer. Let it idle, nothing worse on an engine than starting it.

My two cents.

[mackin]

Ford guuys let them idle for........


If it's running, it aint broke, and half the battle is won...... tongue.gif They'll at least get away from the pump......Be able to get to a BANK'S distributor spend a few grand to beat a stock MAX....... :rolleyes:
Oh the was the other thread ..... OOPS.......

MAC :D

[csimo]

I don't think this is a PSD issue, but rather a diesel issue. It is common for large diesel engines to run 100% of the time. Some are hard to start, others have a hard time retaining enough heat to maintain efficient combustion.

Diesel engines run completely different than gasoline engines. A gasoline engine runs at the same fuel to air ratio at all speeds, and at idle a gasoline engine is not very efficient. A diesel engine runs at variable fuel to air ratios, and runs very, very lean (perhaps 1:100 fuel to air) at idle.

The old rule of thumb for a gasoline engine was that if it was going to idle for more than a minute you should shut it off and restart it to save fuel. A diesel engine can run for perhaps 15 minutes on less fuel than it takes to get it restarted.

The bottom line is that there is no ignition source danger while fueling a diesel engine, the fuel is much less volitile than gasoline, and if it's going to take less than 10 minutes or so you will use less fuel by letting it run rather than shutting it off and restarting.

[Cancerman]

csimo, good points - think I will leave mine running from now on.

Max Rock, I will be looking for you black chevy when I am out your way!

[BlackMax]

There was a case a few years ago of big diesel rig sucking in gas fumes at a tanker loading dock. The diesel could not be shut down and caught it and the loading dock on fire. Before they got it put out I think there were 3 rigs and the dock burned to the ground. Something to think about with gas pumps next to diesel pumps. :eek:

[Amianthus]

I can't believe you guys haven't nailed this one yet.

There are only a couple of reasons to leave it idle for any length of time. One of which was eluded to above. That being the cooling off of the turbo. If you shut down a turbo hot, the heat will burn the oil in the bearings. Repeatedly doing this will cause failure of the turbo. Now, if the Dmax is a liquid cooled turbo, then it wouldn't be much of a problem. But it is still a good idea to let it cool down a little bit before shutting it down.

But too much idling can cause the cylinders to cool down to the point that incomplete combustion will occur and cylinder washdown will start.
Cylinder washdown is a situation when the unburned fuel acts as a solvent on the cylinder walls and washes the lubricating oil from them. Obviously, this can become a serious problem. Although the amount of idling is quite lengthy (some where along the lines of hours).

To answer you original question, idling is a matter of preference. Some people do it because they think that if the big rig's do it, it must be good. That's stupid. I idle mine as long as I need to cool down the turbo. Then I shut it down. But I also have an automatic timer that monitors the turbo temp and shuts down the truck when it reaches a preset temp.
There are some states where it is against the law to fuel while the engine is running (Texas being one). The reason behind this is the low flash point of gasoline. Gasoline vapors can ignite off of the hot exhaust gasses of a running engine. It can also ignite off a catalytic converter, but that's another issue. Diesel, however, will not. It's flash point is considerably higher and hence, shouldn't ignite if the engine is running while fueling. But politicans don't know that, and have just made the law a blanket one.
So idle it if you want to. Or shut it down. It's your decision as to why you want to keep it running or not.

[Jelisfc]

On the subject of diesel run on at gas pumps...been there done that.

I used to haul bulk gas from refineries. Once in a while at the loading terminal if the wind was just right when I turned the rig off it would run on like a tired gasser does. You'd have to have a serious vapor source to get a run away situation but it's possible and probably happened somewhere. Kinda like shooting too much ether. Sends chills knowing you just gotta ride it out!

[Joe.G]

If you use a good synthetic oil you will not have coking problems with your turbo.
All I got to say!

[mdadgar]

Amianthus, the fact that it's a water-cooled turbo is, in this case, not relevant.

If the truck is not running, the water pump is not pumping and there's nothing cooling the turbo bearings but the residual oil in the housing. And that's what causes coking.

Run a good synthetic and idle your truck for a bit after heavy running. Probably not necessary for around-town use.

- Mark

[Amianthus]

Sorry dude, but it is relevent. Normally the oil is the heat sink in a turbo. But in a water-cooled turbo, both the oil and the water are the heat sinks. The water that remains around the turbo has the ability to remove heat from the bearings and housing of the turbo, even if the engine is off. But the oil stops flowing and drains away when the engine shuts down. So there goes the heat sink on a standard turbo. So any heat that you can remove before shutting it down helps.

As for just sticking synthetic in it and blowing all caution to the wind, I don't know if I would do that. I run synthetic and still cool it down. (The following is my opinion only) It would be logical that doing so would beat up on the oil unnecessarily. It may not have as much impact as it would on a conventional oil, but still.

[csimo]

We're off subject here, but I'll throw my two cents in on the turbo oil coking issue.

The exhaust gas temp. (EGT) of a diesel engine is well below that of a gasoline engine. The turbochargers used for diesels are for all purposes identical to those used on gasoline engines. They are designed to withstand the punishment of a gasoline engine.

Since the diesel turbocharger is running several hundred degrees cooler it is difficult to cause oil coking under any circumstances.

I've seen many, many turbocharger take-offs and the difference between the same model turbocharger on a gasoline vs. a diesel engine is considerable.

If you run a diesel hard you won't exceed 1250 degrees EGT for any length of time and keep the engine together. Even if you could manage to shut down after an extended hot run most good oils won't coke at 1250 degrees. Now a gasoline engine can hit 2000 degrees EGT and that will coke even a good synthetic.

I don't recommend punishing your engine by running hot and hard and then shutting it off right away for many reasons including thermal shock (this is a real danger for aircraft engines).

[SledZep]

Yes, yes, yes, all good reasons. But the real reason Ford owners leave them running is so they do not have to talk to us Duramax owners. because their truck needs to be turned off while talking and ours does not. I have done it twice. They say
HEY! IS THAT THE NEW DURAMAX!
I say yes.
they say. IS IT REALLY AS QUIET AS THEY CLAIM?
I say, What?
they say. IS IT REALLY AS QUIET AS THEY CLAIM?
I say, What?
They shut their truck down and I say, what do you think?

:D :eek:

[Cancerman]

After giving this some more thought (windshield time), my action will be to always shut my engine down before refueling. My reasons are:
1. The sign says to!
2. If my engine is hot, I will idle it down before pulling into the pumps.
3. It would be my luck to catch a Soccor Moms van on fire with 10 kids in it! Because she is sitting in the van and the auto-shutoff does not work and gasoline is running on the ground.

The following is kind of long and concerns gasoline, but I think worth the read. Have a safe day!

The Petroleum Equipment Institute is working on a campaign to try and make people aware of fires as a result of "static" (that is, static electricity) at gas pumps. They have researched 150 cases of these fires. The results were very surprising:
1) Out of 150 cases, almost all of them were women.
2) Almost all cases involved the person getting back in their vehicle while the nozzle was still pumping gas, when finished and they went back to pull the nozzle out the fire started, as a result of static.
3) Most had on rubber-soled shoes.
4) Most men never get back in their vehicle until completely finished. This is why they are seldom involved in these types of fires.
5) Don't ever use cell phones when pumping gas
6) It is the vapors that come out of the gas that cause the fire, when connected with static charges.
7) There were 29 fires where the vehicle was reentered and the nozzle was touched during refueling from a variety of makes and models. Some resulting in extensive damage to the vehicle, to the station, and to the customer.
8) Seventeen fires that occurred before, during or immediately after the gas cap was removed and before fueling began.

NEVER get back into your vehicle while filling it with gas. If you absolutely HAVE to get in your vehicle while the gas is pumping, make sure you get out, close the door TOUCHING THE METAL, before you ever pull the nozzle out. This way the static from your body will be discharged before you ever remove the nozzle.

I ask you to please send this information to ALL your family and friends, especially those who have kids in the car with them while pumping gas. If this were to happen to them, they may not be able to get the children out in time.

[hoot]

Shutting you truck down at the pump helps minimize the chance of a spark from any source. Remember, the truck still needs electricity to run and there are lot's of elec motors and solenoids, and relays that could throw off a spark.

Diesel fuel has a lower flash point so there is less concern during diesel refueling than highly volital gasoline. But, today many of us are filling up close to gasoline pumps so we really should be shutting them down. I also believe filling station liability insurance dictates the rule.

Diesel pickup truck drivers like leaving their trucks run cause...

It sounds cool, draws questions

We feel like big rig truckers

We always assumed that since the big guys do it, it must be right. But then did you ever have a conversation with a trucker ;)