Does running out of gas damage the engine?

Tomkins

Member
Joined
Jan 12, 2001
Location
Salt Lake City, UT
I'm not really trying to gain permission to wait until the last minute to fill-up my car. Only trying to verify what I was told about diesel engines and running out of gas.

I've heard that the diesel fuel actually lubricates certain parts of the engine and that running out of gas can cause damage to these parts.

If anybody could shed some light, I would greatly appreciate it.

--Tom
2001 Silver Golf GLS TDI
 

TDI2some

Veteran Member
Joined
May 14, 2001
Location
Western WA
TDI
2005 PassatTDI GLS, 2003 Audi A4q 1.8t, 1975 Rabbit (waiting for TDI transplant)
I'm not sure. It sure is DAMN hard to start after you run out. Almost have to purge the system before it will. It makes sense though when you think about how the fuel lubes the intake tract.
 

RC

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Oct 13, 2000
Location
Maryland`s Eastern Shore
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Two White 96 B4 Wagons
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Tomkins:
[QB]...running out of gas.
...running out of gas.
[QB]<HR></BLOCKQUOTE>

I sure hope you are not putting "gas" in your TDI!


After having gasoline powered vehicles for so long it was difficult for me to switch from the term "gas" to "fuel" when refering to the liquid that powers this fine vehicle.
 
S

SkyPup

Guest
When you run out of diesel fuel it will hurt the fuel pump and injectors due to lack of lubrication while cranking to get fuel into the injectors. It is not good to let the pump run dry, this should be avoided.
 

banzai

Veteran Member
Joined
Oct 28, 2000
Location
East Overshoe, ME
TDI
NB TDI
I have had several cars with no "gas" gauge-
only ran out of gas once- when I was trying to run tank low to drain it!

I saw an engine/car catch fire when someone was trying to prime carburettor- car was a public nuisence anyways!
 
M

mickey

Guest
No. It's not harmful to the engine. When you turn off the key you've basically "running it out of gas."

A gasoline engine misfiring as the tank empties can damage the catalytic converter, but I don't think that applies to a TDI.

You will have a lot of trouble getting it restarted, though. All that cranking isn't good for the battery or starter motor, and probably isn't the friendliest thing for the injector pump either. If you run out of fuel, pull the "hairpin" on top of the filter and pull out the temperature control valve. Don't disconnect the hoses. Pour straight Power Services additive, or some other good fuel additive, directly into the filter and fill it up. That will reduce the cranking time needed to get the engine started. It'll still need a minute of cranking or so. (In 10 second intervals, with 10 seconds "rest" between them.) And it'll run rough and probably "kill" a few times until things get working again.

-mickey
 
M

mickey

Guest
I would disagree with SkyPup on one thing: Without fuel in the pump and injector lines the injectors won't function. Therefore, running out of fuel cannot harm them. They're forced open by fuel pressure.

Running the pump "dry" is a concern, but it won't be completely "dry". Still...it's not good for the injector pump by any means.

-mickey
 

naturist

Veteran Member
Joined
Apr 2, 2001
Location
Bro Jerry's hometown, Virginia
TDI
2001 Jetta TDI, 2005 Jeep Libby CRD, 2012 BMW X5 35d
As others have noted, running a VW TDI out of fuel is a bad idea, for all the reasons noted.

It should also be noted that older/other diesel engines will be more sensitive to this issue, though few will be less sensitive. On a lot of other diesel engines, running out of fuel is a major catastrophe, requiring replacement of fuel pumps and injectors. I know because a friend of mine foolishly ran a farm tractor dry, and it cost $600 for a new fuel pump to get it running again. And that was 10 years ago. I shudder to think what it would cost today.

Ask any long-haul trucker with some experience: those guys do NOT run out, if they get that close, they shut 'er down and hike instead, if they can't raise help on the CB.

While you won't kill your injectors or fuel pump on a VW TDI, as they make minimal use of fuel for lube, their lives will not be lengthened at all either!
 

weedeater

Top Post Dawg
Joined
Mar 17, 2001
Location
Reston, VA
TDI
Jetta, 2001, Baltic Green
<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> I ran my TDI engine for 6 miles without any fuel <HR></BLOCKQUOTE>

I hope it was all downhill!
 

**DONOTDELETE**

New member
Joined
Dec 31, 1969
I bet it was all uphill...

Is there a pump in the tank? The dealership said that could be fried if you ran out of fuel.

Someone said once the pump isn't strong enough to self-prime. Do the injector lines have to be bled if one runs out of fuel? I sure wouldn't want to run out of fuel...


[ June 26, 2002, 15:59: Message edited by: je ]
 

solstar

Veteran Member
Joined
Apr 18, 2001
Location
Texas
TDI
2013 NB red cabrilet
it used to but not any more-- that's the beauty of mechanical fuel injection vs electronic fuel injection- priming fo the mechanical system is messy and not so with electronic system!
 

MOGolf

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underneath something
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2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
je, Your TDI has 1 pump on it. That is attached to the engine. None in the tank. That's a gas fuel injection thing.

If it runs dry, using a hand vacuum tool to suck out air and get the fuel up through the fuel lines, filter, and prime the pump is recommended in the service manual. Pre-filling the filter helps, but still leaves air in the line from tank to filter. Any method of priming, or partially priming, the fuel system is better than cranking and cranking and cranking until fuel is going through the system again.

Best of all, just don't run out of fuel.
 
M

mickey

Guest
If you run it dry, here is the best way to get it restarted while minimizing dry cranking:

1. Fill the fuel filter with fuel. Use a syringe or something to squirt fuel into the rubber lines that attach to the filter.

2. Use a 17mm line wrench to loosen, but DO NOT REMOVE, one or two injector line fittings at the injectors.

3. Crank the engine until it barely shows signs of wanting to start...then SHUT IT OFF. Fuel will squirt out of the loose fittings under high pressure!

4. Tighten the fittings, and start it up.

This method gets the air purged out of the lines more quickly. It'll only run on one or two cylinders for several seconds, but the important thing is that it'll RUN...and fuel will be circulating through the pump.

-mickey
 

tadc

Top Post Dawg
Joined
Apr 13, 2001
Location
Stumptown
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Golf GLS TDI, '01, Black
Originally posted by je:
Ok, what does that plug into?
And if the tank is full, isn't the fuel line full to the level of the tank?
<font size="2" face="Verdana, Helvetica, sans-serif">you use the vacuum device to suck on the outlet of the filter until it's full of fuel again.

Or, you could connect it to the outlet of the pump and suck fuel into the pump.
 

**DONOTDELETE**

New member
Joined
Dec 31, 1969
I have a confession: It was me who ran out of fuel


By this morning the filter was full!
Nothing gets siphoned out of the pump outlet.

Only letting air out of the injector lines gets fuel to the injectors. But what a mess - put something cloth around the injector line you loosen.

 

Huck

Well-known member
Joined
Aug 5, 2000
Location
NH, US
Velevetfoot, I am with you. The MityVac works great to prime the pump. I got mine for twenty bucks and is a great thing to have in ones arsenal of tools.

When I did my timing belt, I changed the filter at the same time and lost the prime of the pump.
This thing was the answer.
 

christi

Top Post Dawg
Joined
Feb 22, 1999
Location
Ruislip, Middlesex, UK
TDI
Peugeot 806, 607
My wife's Audi 80 TDI got some splits in the injection leak off pipes, causing the engine to run on a fuel/air mixture if the accelerator was pressed too hard. The engine would kind of jolt for a fraction of a second if two much power was demanded.

She drove it like this for maybe a hundred miles till I figured out what the problem was.

At the same time the needle lift sensor in the 3rd injector quit, so once the leak off pipes were replaced I also needed a new (used) 3rd injector.

Coincidence? I suspect not.

I also heard of a guy who towed a TDI around 5 miles attempting to get it to start. It wouldn't because there was no fuel supply


Anyhow, it wrecked the injection pump.

On the other hand, if you simply run out of fuel, refill it and get it going again, then I can't imagine it doing any harm.

I always put a lubricity additive in my fuel. I think that it will help in cases like this.
 

dzcad90

Rolex & gin
Joined
Mar 15, 1999
Location
Joliet, IL USA
TDI
Jetta - 97 (RIP), '03 (Sold), '09
Heck, I just use a small funnel to pour additive right into the fuel filter until it comes to the top. You do have to do this a few times, as the material in the filter seems to absorb some of the fuel, or it just takes a while to settle.
 
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