Anybody try to run their TDI out of Diesel to see exactly how many miles they can get

[charley654]

The engine will not run too long without fuel,
if the HPFP does not get fuel it can't build enough pressure have the injectors spay, the engine will quit running. If the engine does not run/turn, the HPFP does not turn. Crankshaft and HPFP are connected.

 

[Shife]

The engine will not run too long without fuel,
if the HPFP does not get fuel it can't build enough pressure have the injectors spay, the engine will quit running. If the engine does not run/turn, the HPFP does not turn. Crankshaft and HPFP are connected.

Drain the oil pan and run the engine if you think this is a trivial matter. You are doing the same kind of damage with fuel starvation at the HPFP. Considering the lubricity challenges of ULSD that are well known, I would not be so cavalier with running low on fuel.

Trying to run the tank down to fumes is stupid. The lift pump is cooled by residual diesel in the tank. Very low tank = no heat transfer from pump to surrounding fluid = shortened lift pump life span. Running the HPFP out = immediate accelerated wear, no different than oil starvation in an engine crankcase.

Cars are pretty smart these days, but they still haven't managed to make them idiot proof. I used to make a lot of money off of some of those idiots.

 

[charley654]

Drain the oil pan and run the engine if you think this is a trivial matter. You are doing the same kind of damage with fuel starvation at the HPFP. Considering the lubricity challenges of ULSD that are well known, I would not be so cavalier with running low on fuel.

Trying to run the tank down to fumes is stupid. The lift pump is cooled by residual diesel in the tank. Very low tank = no heat transfer from pump to surrounding fluid = shortened lift pump life span. Running the HPFP out = immediate accelerated wear, no different than oil starvation in an engine crankcase.

No.....draining the oil is not the same as running out of fuel.
If you remove oil form the engine while it is running it will continue to run for a while till things heat up from friction and seize. (Unless low oil pressure sensor tells the computer to stop the engine).
If you remove fuel or fuel pressure form a common rail diesel it will stop right away. Meaning you will not run things dry.

Again, I am not advocating to the run the car out of fuel, but if you do, I don't think the sky will be failing and zombies appear from the wood.

 

[Shife]

No.....draining the oil is not the same as running out of fuel.
If you remove oil form the engine while it is running it will continue to run for a while till things heat up from friction and seize. (Unless low oil pressure sensor tells the computer to stop the engine).
If you remove fuel or fuel pressure form a common rail diesel it will stop right away. Meaning you will not run things dry.

Again, I am not advocating to the run the car out of fuel, but if you do, I don't think the sky will be failing and zombies appear from the wood.

You are wrong. There is plenty of information available to educate you, but you appear happy to have your head stuck in the sand. Accelerated wear occurs immediately upon oil starvation in an engine or fuel starvation in a HPFP. You may not "see" any effect, but it is there. Residual pressure in the rail will allow a HPFP to happily grind itself apart for a short period of time under a fuel starvation scenario. The engine does not immediately come to a halt upon pressure drop in the rail, and by the time the rail pressure has dropped enough to produce an uncombustible spray pattern, the HPFP has already experienced fuel starvation. The lift pump is also being damaged while this is occuring as it now has zero fuel to cool itself with.

Good luck finding a car that shuts itself off due to low oil pressure. Ain't happening. It would be in violation of federal motor vehicle standards to have a vehicle programmed to shut down while being operated due to something like you describe. Your lawn mower will shut itself off due to low oil press. Your family sedan will not. If I need to explain this further, there is no hope for you.

I don't know about you, but I actually used to do this crap for a living. I now work in an engineeing field more related to industrial machinery, but lubrication challenges in moving components exist here as well. You can believe whatever the hell you want, but you aren't even close to being right on this subject.

 

[psd1]

It appears that if you run your precious VW diesel out of fuel it may just never start again. You know, because the heat that will occur for running hundreds of miles without the lubricity of the fuel will kill the HPFP. If you were to ever be fortunate enough to put lube, err I mean fuel back in it it's quite likely that it would never start because…AIR! You know, the kind of air that gets in when you change the fuel filter…

You guys kill me, seriously!

 

[C C]

What's the reasoning behind running out of fuel on purpose? No one in their right mind incapacitates a perfectly good vehicle. If that's what anyone wants to do, have at it and tell us all about it. I'll live vicariously through you.

 

[xjay1337]

I haven't seen any tests on a CR but on a 1.9 PD engine here in England someone on another forum did a test and they went 120 miles (from memory) from the fuel light coming on to the car dying. I think 74 of them or something were with 0 range showing.
Not forgetting the range calculator is based on a fuzzy logic on your last sort of ~ 20 miles of driving so will vary quite substantially.

 

[Shife]

It appears that if you run your precious VW diesel out of fuel it may just never start again. You know, because the heat that will occur for running hundreds of miles without the lubricity of the fuel will kill the HPFP. If you were to ever be fortunate enough to put lube, err I mean fuel back in it it's quite likely that it would never start because…AIR! You know, the kind of air that gets in when you change the fuel filter…

You guys kill me, seriously!

Nobody is saying this. If you remove or reduce the lubricity a moving component requires, advanced wear will occur. In the case of a diesel HPFP that wear can occur very rapidly. Does this mean the part is now immediately garbage? No, it does not. But to have a cavalier attitude and claim no harm is done is false and ignorant of how these components operate.

 

[charley654]

If you can remain civil, stop the name calling... I'll be glad to discuss it with you.
You may be right; lets talk about it.
Looking at the drawing it appears the internals of HPFP are sitting in a cavity/tub of diesel fuel. It does not pull/such the fuel from this cavity.
When you do not give it any more fuel, the fuel the tub does not run dry or drain out. There is plenty to lubricate parts, It will just not produce pressure for the common rail.
I am sure the stupid engineers designed it to be somewhat fool proof, no?
There maybe a pressure sensor as well if the pressure drops it kills the engine? Let me summon some VW engineers to chime in... wait they may lie to us..

 

[showdown 42]

Is all of this discussion involving how far one goes on a tank. REALLY, What could be less important than how far you can go at zero fuel gauge. Don't play with a stick of lit dynamite just for the fun of it,unless money is of no interest to you. Fill up at 1/4 tank.

 

[charley654]

I don't think people intentionally try to run the car out of fuel, but it surely does happen.
I would think used and new car dealers do it frequently since they don't keep much fuel in the car and the cars get moved around.
A new PDI car (pre-delivelry inspection) at the dealer does not get filled with fuel until it is about to get sold.
The car comes off the delivery truck with minimal fuel, service tech grabs it, drives it to the shop does the PDI, and parks it back on the lot. Sales staff moves the car around randomly.
Many motorist run out of fuel on the roadways every day, some bound to be diesels. Are they all damaged goods?
When the CR TDI runs out of fuel, it will start knocking like a son-of-a Bi#@$%h, (at idle).
I am guessing because not the proper amount of fuel is sprayed in to the cylinder.
I've parked a TDI on steep hill with low fuel and that is what happened.
Filled it with 5 gallon form a can... and life goes on.

 

[Sosin]

I don't think people intentionally try to run the car out of fuel, but it surely does happen.
I would think used and new car dealers do it frequently since they don't keep much fuel in the car and the cars get moved around.
A new PDI car (pre-delivelry inspection) at the dealer does not get filled with fuel until it is about to get sold.
The car comes off the delivery truck with minimal fuel, service tech grabs it, drives it to the shop does the PDI, and parks it back on the lot. Sales staff moves the car around randomly.
Many motorist run out of fuel on the roadways every day, some bound to be diesels. Are they all damaged goods?
When the CR TDI runs out of fuel, it will start knocking like a son-of-a Bi#@$%h, (at idle).
I am guessing because not the proper amount of fuel is sprayed in to the cylinder.
I've parked a TDI on steep hill with low fuel and that is what happened.
Filled it with 5 gallon form a can... and life goes on.

Yeah I was just thinking hypothetically. Like if you're on a road trip and there's not a diesel station for like 100 miles. You know how far could you make it? Any smart person would definitely plan ahead but sometimes accidents happen and we don't plan accordingly. I was just trying to see how far people got after the fuel gauge read "0". It doesn't matter to me any more anyways as I wrecked my car driving over a center median. $3,200 worth of damages.

Ronnie

 

[Shife]

If you can remain civil, stop the name calling... I'll be glad to discuss it with you.
You may be right; lets talk about it.
Looking at the drawing it appears the internals of HPFP are sitting in a cavity/tub of diesel fuel. It does not pull/such the fuel from this cavity.
When you do not give it any more fuel, the fuel the tub does not run dry or drain out. There is plenty to lubricate parts, It will just not produce pressure for the common rail.
I am sure the stupid engineers designed it to be somewhat fool proof, no?
There maybe a pressure sensor as well if the pressure drops it kills the engine? Let me summon some VW engineers to chime in... wait they may lie to us..

It is in violation of Federal law to have the powertrain shut down due to the scenario you describe. A vehicle operated on public roadways can not be designed to operate as you describe. Your lawnmower? You bet that thing will shut down if the oil press drops. Your car? Not a chance.

I'm well aware of how a HPFP works. I don't know how else to explain this to you. Wear occurs during normal operation with proper lubrication in place. Remove or reduce that lubrication and advanced wear WILL occur. In the case of a HPFP that wear can occur very rapidly. Simply contaminating a diesel tank with a small amount of gasoline is enough to cause damage.There is no free lunch. Engineers do not design components to be idiot proof.

 

[rwolff]

It is in violation of Federal law to have the powertrain shut down due to the scenario you describe. A vehicle operated on public roadways can not be designed to operate as you describe. Your lawnmower? You bet that thing will shut down if the oil press drops. Your car? Not a chance.

On my truck, if the oil pressure drops the "stop engine" light comes on, and it will shut down in a minute unless the timer is reset by pressing the "diag" button (shows DDEC codes if pressed with the engine on and the parking brake engaged). On the Ford Powerstroke, losing oil pressure shuts the engine down IMMEDIATELY - its unit injectors are powered by oil pressure, so no oil pressure, no fuel.

 

[Drivbiwire]

It appears that if you run your precious VW diesel out of fuel it may just never start again. You know, because the heat that will occur for running hundreds of miles without the lubricity of the fuel will kill the HPFP. If you were to ever be fortunate enough to put lube, err I mean fuel back in it it's quite likely that it would never start because…AIR! You know, the kind of air that gets in when you change the fuel filter…

You guys kill me, seriously!

You aren't too far off...

If you get enough air entering the system prior to the engine shutting of f(read seconds) the injectors will not fire and will require a mechanical reset...not kidding.

Don't run a common rail out fuel.

I've had issues with injectors sent after overhaul/repair by us. The mechanics despite their best efforts got enough air into the system that they would not re-prime.

We got them back, reset them, and the fired off perfectly after resetting them.

They are extremely sensitive to air, and if you get enough in there, it will have you chasing your tail trying to figure out why the car won't start despite having all the air removed.

One more thing, yes fuel lubricates the fuel system, but just as importantly it cools the system! The fuel removes heat that is generated inside the injector and transfers that to the fuel cooler and then the tank.

The tank acts like a large heat sink, run low on fuel and that fuel gets hotter and hotter due to less mass to hold that heat.

1/8 th of a tank is my general rule or low fuel light, sufficient COOL fuel is critical to system function.