# How bad is it to run out of diesel? Bleed the system?



## MDTurborocco (Aug 24, 2003)

Im starting to drive my 97 passat more and I want to fill it all the way to the top and run it all the way till empty. Would it be as easy as filling it up with a gallon or two when empty and just turning over the engine till it starts? TIA


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## V-TEC this!!! (May 4, 2003)

*Re: How bad is it to run out of diesel? Bleed the system? (MDTurborocco)*

Once you run the car out of diesel...you will need to bleed the system....diesel also lubricates the pump. So running the pump low on diesel can cause damage.


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## Ian'89Fox (Mar 14, 2001)

*Re: How bad is it to run out of diesel? Bleed the system? (MDTurborocco)*

That's right, don't run a diesel engine out of fuel. I don't see why you'd want to anyway.


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## chittychittybangbang (May 28, 2007)

*Re: How bad is it to run out of diesel? Bleed the system? (MDTurborocco)*

It's not good. You have no electric fuel pump to prime the system. When you run out of fuel, the lines will have some air in them. Plus, it's a safety hazard to drive along and then run out of fuel in the middle of an intersection, highway, etc.
Edit: Yes the injection pump is self priming but you might run down the battery or fry the starter before you get the engine to start if you're that dry. The best way to restart it is to manually use suction at the return fuel line at the injection pump (engine) to draw fuel all the way through the lines. Don't keep cranking if you have no fuel since it just sucks in more air.
If you want to see your max range, drive until almost empty. Open the top of the fuel tank. It's in the back, it looks like a little port. Remove the fuel level sender. Suck out all the fuel in there and then measure it. Use the same pump so that the calibration will be the same and you know how much fuel you are getting.



_Modified by chittychittybangbang at 6:22 PM 5-27-2008_


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## MDTurborocco (Aug 24, 2003)

*Re: How bad is it to run out of diesel? Bleed the system? (chittychittybangbang)*

I was gonna do this to figure out mpg. I drove it the other day at 12 gallons and over the day drove only 40 miles and it went down to 10..... I just started driving this car, it has diesel from at least 6 months ago if that matters. Thanks for the suggestions though


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## Ian'89Fox (Mar 14, 2001)

*Re: How bad is it to run out of diesel? Bleed the system? (MDTurborocco)*


_Quote, originally posted by *MDTurborocco* »_I was gonna do this to figure out mpg. I drove it the other day at 12 gallons and over the day drove only 40 miles and it went down to 10..... I just started driving this car, it has diesel from at least 6 months ago if that matters. Thanks for the suggestions though

To figure out your mpg, do the following:
-Fill tank to the very top, or first click on pump (has to be roughly the same on every fill-up)
-Reset your trip odometer
-Drive until you need to fuel up
-Fill tank to the same spot as previous
-Note miles driven and gallons of fuel added, then just do your calculations http://****************.com/smile/emthup.gif


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## Tim Birney (Jun 2, 2003)

*Re: How bad is it to run out of diesel? Bleed the system? (Ian'89Fox)*

... or just fill up, keep a receipt, make a spreadsheet of the Gallons, Miles, and MPG.
Average the entire spreadsheet from beginning to end.
If you want a 350 mile tank average, then you could get picky about HOW you fill each tank.
(I have tanks, in the MKV Jetta, of 48 MPG, and 31 MPG, and overall 36 MPG, I do a lot of City driving. If you travel 500 miles on the Highway, your spreadsheet will reflect the good MPG, if you drive consistently in the City, then you will eventually see your true City MPG.)
My B5.5, 2.0L Passat is very religious at 30MPG in the city, and 40MPG on the highway, and how I fill that beast does not play into the picture. 
Just don't run it dry, take the overall average.
http://****************.com/smile/emthup.gif


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## MDTurborocco (Aug 24, 2003)

*Re: How bad is it to run out of diesel? Bleed the system? (Tim Birney)*

roughly 750 miles out of my first tank not bad http://****************.com/smile/emthup.gif Did I hear a quart of atf is good for the injection pump??


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## Fat Jon (Feb 27, 2007)

*Re: How bad is it to run out of diesel? Bleed the system? (MDTurborocco)*


_Quote, originally posted by *MDTurborocco* »_roughly 750 miles out of my first tank not bad http://****************.com/smile/emthup.gif Did I hear a quart of atf is good for the injection pump??

1 oz ATF (or 2 stroke motor oil) to 1 gallon of diesel is the general rule..


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## RabbitJockey (Nov 25, 2004)

you don't need to bleed the system? you just add fuel and crank till it starts, it bleeds itself


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## RabbitJockey (Nov 25, 2004)

also atf is corrosive to the ip, i wouldn't run it regularly, although i think its good to run a quart through every once in a while


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## Mr Bungle (Mar 23, 2008)

*Re: How bad is it to run out of diesel? Bleed the system? (Fat Jon)*

And if you are going to use 2 stroke oil use ashless or smokeless, same thing. 
It is clean and not full of carbon particles that can score your injectors at their high pressure. especially for like tdi pressure.


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## Tinker Toy (Sep 13, 2005)

*Re: How bad is it to run out of diesel? Bleed the system? (Mr Bungle)*


_Quote, originally posted by *Mr Bungle* »_And if you are going to use 2 stroke oil use ashless or smokeless, same thing. 
It is clean and not full of carbon particles that can score your injectors at their high pressure. especially for like tdi pressure.

This is off topic but carbon particles may not be as bad as stated and last I heard, graphite is a good lubricant. Check out the following site:
http://www.embedded.com/story/OEG20010618S0078
Otherwise Google Cummins Centinel.


_Modified by Tinker Toy at 11:42 PM 5-24-2008_


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## QuantumSyncro (Apr 28, 2000)

*Re: (Trev0rBr)*

The IP has an internal lift pump so priming is automatic. OTOH, it creates a lot of wear and tear on the starter to prime the system every time you run out of fuel.
Additionally, the IP has an internal reservoir that holds enough fuel to lubricate the pump but not enough to push to the injectors, so running out of fuel won't draw all the fuel out of the IP.
It's preferable never to run out of fuel. The only priming you want to have to do on a diesel is when you change the fuel filter.


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## RabbitJockey (Nov 25, 2004)

word. mine always started in a few cranks as long as i put the pedal down a good bit. the longest it ever took for a car to start for me was when i did my td swap. took forever.


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## Fat Jon (Feb 27, 2007)

*Re: (Trev0rBr)*


_Quote, originally posted by *Trev0rBr* »_word. mine always started in a few cranks as long as i put the pedal down a good bit. the longest it ever took for a car to start for me was when i did my td swap. took forever.

yeah, i've got to hold my pedal down a good bit to get it started as well... any idea why that is ? why wont it just start up, my diesel truck does. lol


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## RabbitJockey (Nov 25, 2004)

i just do it because i figure it will help bleed the pump faster since its trying to move more fuel.


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## Fat Jon (Feb 27, 2007)

im gonna test my glowplugs


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## Mr Bungle (Mar 23, 2008)

*Re: (QuantumSyncro)*


_Quote, originally posted by *QuantumSyncro* »_The IP has an internal lift pump so priming is automatic. OTOH, it creates a lot of wear and tear on the starter to prime the system every time you run out of fuel.
Additionally, the IP has an internal reservoir that holds enough fuel to lubricate the pump but not enough to push to the injectors, so running out of fuel won't draw all the fuel out of the IP.
It's preferable never to run out of fuel. The only priming you want to have to do on a diesel is when you change the fuel filter.

Good to know, thanks


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## transient.labor (Jan 11, 2007)

*Re: (Mr Bungle)*

I've run mine out of fuel twice unintentionally and once intentionally. You can easily restart the engine after refueling if you don't try to get every last drop out of the tank and lines. 
As soon as you feel the engine losing power, the pump is sucking air. Immediately stop the car, refuel and the pump should prime instantly. 
Don't keep trying to start the car without refueling because the more air that enters the system the harder the car will be to restart.


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## OttoSchultz (Apr 16, 2004)

*Re: (transient.labor)*

TDI's and Rabbit are _very_ different creatures. ATF is NOT recommended for TDIs. Also, the drive-by-wire function can do some funky things. Putting the pedal to the floor while cranking won't necessarily help in getting the car re-started after running out of fuel.
In theory, the injection pump is self priming, but many people have found from experience, that this is not always the case. Just try putting a new fuel filter on the car totally empty, and see what happens. 
My GF was driving us home one night, she woke me up at 1am to say we had run out of fuel. We were about 2 miles from the Blanford service station on I90, about halfway between exit 2 & 3. We called AAA and waited. The truck showed up finally and the driver dumped in 5 gallons of Diesel. I didn't have a funnel or other convenient way to pre-fill the filter, nor a vacuum pump to draw fuel to the IP. After cranking until the battery started dying, the car still wouldn't start. The driver refused to tow us and leave us at the next service area, but took us 20 miles back to exit 2 in Lee, and dropped the car at the truck stop, which was all but deserted. Since the battery was pretty weak at this point, the clerk helped to jump start the car. The cables were only hooked up for 30 seconds and it fired right up.
So the self-priming fuel pump is sort of self-priming, eventually.


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## MDTurborocco (Aug 24, 2003)

*Re: (OttoSchultz)*

Thank you for everyone that has posted, this is exactly the information I was looking for and overall a very informative post. So really atf is not needed? I got this thing at 170k miles with no previous history im just trying to do everything possible to keep it tip top and keep the injectors/IP in good working order http://****************.com/smile/emthup.gif


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## OttoSchultz (Apr 16, 2004)

*Re: (MDTurborocco)*

Don't use ATF. Go over to http://www.tdiclub.com and do a search there in the Fuel & Lubricant section, and you'll get a whole bunch of reasons not to use ATF.


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## RabbitJockey (Nov 25, 2004)

pressing the pedal down will help it prime faster since the plunger will stroke further


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## OttoSchultz (Apr 16, 2004)

*Re: (Trev0rBr)*

Not in a TDI. There's no cable from the pedal to the pump, so the ECU controls how much is injected during startup. Stepping on the pedal won't help reprime a TDI.


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## Jazz555 (Jan 11, 2013)

I think its right, don't run a diesel engine out of fuel.


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## samdbgt (Apr 16, 2015)

If it is an old model then it might become a big headache for you. You will have to pour in at least 3 litres of diesel and pump the engine to throw out the air. Only then will the vehicle start. 






--------------------------
SAM JAMES
Medical Billing
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## Volkswagens-for-life (Jun 24, 2013)

I know this is an old post, but never, _ever_ run a diesel out of, er, um.. _diesel._ It takes lots of work to get it purged back through the system again. it's not like a gasser where you turn the key, crank it, and she lights up.


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## MXTHOR3 (Jan 10, 2003)

Volkswagens-for-life said:


> I know this is an old post, but never, _ever_ run a diesel out of, er, um.. _diesel._ It takes lots of work to get it purged back through the system again. it's not like a gasser where you turn the key, crank it, and she lights up.


It is if you've got an in tank lift pump  (ie any of the PD or CR cars)


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## Volkswagens-for-life (Jun 24, 2013)

I had a lift pump in my alh, and it was NOT that easy. I'd still rather sweat and push-start the car instead of cranking my battery dead and then hoping to find somebody to jump the car to finish purging the air


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