Running out of gas = damage to car

[PlainJain]

A co-worker told me that her daughter ran out gas in their new car and it caused $1000 dollars of repair bills. She claims that new cars use an injection system that will be damaged by an empty gas tank. I know it's a silly question but she's a a smart woman and she swears it's true.

[statsman1982]

AFAIK, the theory goes that sediment in the bottom of the gas tank will get sucked up in concentrated form by whatever feeds the fuel injectors and gunk up the engine. Having a full gas tank keeps the sediment from concentrating.

That's the theory, anyway. I'm not sure if it's true, but anecodtally, I can tell you that I haven't known anyone that this has caused damage to.

[Gary T]

In-tank electric fuel pumps (pretty much standard for years now) are designed to remain immersed in liquid, which lubricates and cools their moving parts. Running dry can damage them. Some pumps are more sensitive to this than others, but it's not unheard of for even a single incident of running out of gas to cause a pump to fail in short order. Pump replacement costs vary with different vehicles, but I'd say an average is in the 500 range. If it's a European car, 1000 would not surprise me.

[Gary T]

Originally Posted by statsman1982

AFAIK, the theory goes that sediment in the bottom of the gas tank will get sucked up in concentrated form by whatever feeds the fuel injectors and gunk up the engine. Having a full gas tank keeps the sediment from concentrating.

That's the theory, anyway. I'm not sure if it's true, but anecodtally, I can tell you that I haven't known anyone that this has caused damage to.

Neither have I. I've heard that explanation for decades now, but never seen evidence that it actually occurred. The fuel pick-up tube is always in the same place, very near the bottom of the tank at one spot. I would think sediment would have to travel laterally across the bottom surface in order to collect in such a way as to matter, and I can't see how that would happen.

Note also that in the OP's case, it's a new car which wouldn't have any sediment to speak of.

[manila]

Could it possibly have been a diesel engine. They don't like to be run dry and bleeding air from injectors is a pain.

[Zsofia]

I had a very expensive repair when my fuel gauge died and my boyfriend ran out of gas in my car. The problem was that fuel stuff cooling issue, all sorts of assemblies had to be replaced, and it cost me a thousand bucks before the day was done. In Charleston. Which is not where I live.

[groman]

Originally Posted by Zsofia

I had a very expensive repair when my fuel gauge died and my boyfriend ran out of gas in my car. The problem was that fuel stuff cooling issue, all sorts of assemblies had to be replaced, and it cost me a thousand bucks before the day was done. In Charleston. Which is not where I live.

Can you be more specific as to what happened? Did you fill up after and the car started misbehaving? If so, in what way -- what would be the symptoms?

[Gbro]

Some cars can be repaired with replacing just the pump (and intake strainer) rather than replacing the entire assembly. GM is common this way where Dodge is not
This could save a lot of money.
I have also heard that water will destroy a fuel pump very rapidly.
I was also told that an injector cleaner or similar product could dislodge buildups in the intake strainer.
And a gunked up intake strainer can starve a pump leading to failure. The last pump I replaced in my pickup had a very clogged strainer.
Therefore regular use of fuel system cleaners is better than waiting for symptoms and then trying to preform miraculous things.

[Machine Elf]

You could pour a friggin bucket of sand in the fuel tank if you wanted to; it won't make it to the engine. The pump (the first thing fresh, sediment-laden fuel sees) might get destroyed, but there is a filter immediately downstream of the pump, so nothing else will be harmed.

$1000 sounds like an awful lot for a new fuel pump, even including labor to drop/reinstall the tank (pump typically resides in tank). If OP hasn't seen the actual repair bill, I'd guess:

A) the coworker is exaggerating/lying, or
B) the coworker's daughter got scammed by the mechanic for a bunch of extra crap she didn't really need.

[Roderick Femm]

I was told by my father, who drove a Prius, that it would be disastrous to allow it to run out of gas; I don't know exactly why, but my impression was that it would really mess up the (very elaborate) electronics. So ask if the new car was a hybrid, maybe that's why it was so expensive to fix.


Roddy

[Zsofia]

Originally Posted by groman

Can you be more specific as to what happened? Did you fill up after and the car started misbehaving? If so, in what way -- what would be the symptoms?

I'm trying to remember exactly what had to be replaced (and I called around to a few local places to make sure I wasn't being taken for a ride, and they all said it was the same thing - evidently a very high labor job.) The boyfriend was driving down to Charleston and the car just, you know, stopped running. (Because it was out of fuel.) The fuel gauge had stopped at a quarter tank or something and he hadn't noticed. So that broke first, and then he drove it completely out of gas. They told me that the whole fuel system is cooled by the fuel itself, so the fuel pump and I guess everything associated with it were completely fried and it all needed to be replaced, including of course the faulty gauge assembly that started the whole thing. I can't for the life of me remember exactly which things needed to be replaced, but it was just under a thousand bucks with labor.

[Machine Elf]

Originally Posted by Roderick Femm

I was told by my father, who drove a Prius, that it would be disastrous to allow it to run out of gas; I don't know exactly why, but my impression was that it would really mess up the (very elaborate) electronics. So ask if the new car was a hybrid, maybe that's why it was so expensive to fix.

There's nothing special about the fuel injection system on a Prius. Same as other modern cars: fuel circulates through pump, filter, injectors, backpressure regulator, and (whatever doesn't get squirted out of the injectors) back to tank.

Originally Posted by Zsofia

They told me that the whole fuel system is cooled by the fuel itself...

The fuel pump does rely on fuel for cooling, but there's nothing else in the fuel system that runs particularly hot. The only other thing that gets slightly warm is the injectors themselves, and that's almost entirely because of engine heat. They are cooled by fuel flowing through them as a result of injection events; they aren't particularly cooled by the fuel circulating past their top end in the fuel rail. And as soon as fuel stops flowing through the fuel system, guess what - the engine stops running! As far as the injectors are concerned (and anything else in the fuel system except the pump), it's exactly as if you had simply turned the key off.

[Jormungandr]

Originally Posted by Gary T

Neither have I. I've heard that explanation for decades now, but never seen evidence that it actually occurred. The fuel pick-up tube is always in the same place, very near the bottom of the tank at one spot. I would think sediment would have to travel laterally across the bottom surface in order to collect in such a way as to matter, and I can't see how that would happen.

Note also that in the OP's case, it's a new car which wouldn't have any sediment to speak of.

I've never personally seen it, but have seen it on TV. On the first episode of "Mythbusters," they bought a 1967 Chevy (for the Jet Assisted Take Off Car myth) which suddenly stopped running. The reason, the fuel filter was clogged by rust from the gas tank. Simply replacing it got the car running.

[Ionizer]

My son's wife ran his ~ '00 Chevy S-10 truck out of gas, just once, and he had to replace his fuel pump. About a year ago, fwiw. It took him and another person most of a day to lift the bed off the truck to get at the pump and reinstalled. It took four more trips (and install/pulling-out 'new' pumps) before he was given a 'working' pump from the parts-store (!). Parts-store (national chain) had lots of complaints/returned pumps with a manufact-rep coming to town to see what was up...piss-poor workmanship basically.

In the end, it took five pumps, with each one installed/pulled, to get it running again. All from his wife running out of gas after passing the store with cash in pocket she was given to purchase gas...all in all, it could've easily hit $1000 in labor alone if he, me, and a friend had no idea of what to do for repairs. Things are not as easy/cheap as the ol' shade-tree fixing-cars days ;-) Just sayin'.....

[Harmonious Discord]

I think you need to insist on this lady telling you what was damaged and the procedures they had to do that cost $1,000.

[Jormungandr]

Originally Posted by Ionizer

My son's wife ran his ~ '00 Chevy S-10 truck out of gas, just once, and he had to replace his fuel pump. About a year ago, fwiw. It took him and another person most of a day to lift the bed off the truck to get at the pump and reinstalled. It took four more trips (and install/pulling-out 'new' pumps) before he was given a 'working' pump from the parts-store (!). Parts-store (national chain) had lots of complaints/returned pumps with a manufact-rep coming to town to see what was up...piss-poor workmanship basically.

In the end, it took five pumps, with each one installed/pulled, to get it running again. All from his wife running out of gas after passing the store with cash in pocket she was given to purchase gas...all in all, it could've easily hit $1000 in labor alone if he, me, and a friend had no idea of what to do for repairs. Things are not as easy/cheap as the ol' shade-tree fixing-cars days ;-) Just sayin'.....

If I may add that the needle has to stay at "E" for some time. John Stossel, formerly of ABC, drove over 40 miles (correct me if I'm wrong) on an "empty" tank. Apparently European gas gauges are more accurate where "E" is actually empty while we Americans want some insurance. You know you're low on gas and then it hits "E" and you keep going?

Personally, I've run out of gas once. I had the fuel pump replaced in a 77 Nissan (my father's friend did it all in the street), but the wire for the fuel gauge wasn't re-attached. Fortunately, I was 2 blocks from home and a 5 gallon gas can, which was for my lawn mower.

[Tapioca Dextrin]

I've never run out of gas, but I once bought ten gallons of gas and two gallons of water. It totalled the fuel pump. The cost of replacing the pump, cleaning the injectors and draining all the lines was around $1300.

[Gary T]

Originally Posted by Jormungandr

I've never personally seen it, but have seen it on TV. On the first episode of "Mythbusters," they bought a 1967 Chevy (for the Jet Assisted Take Off Car myth) which suddenly stopped running. The reason, the fuel filter was clogged by rust from the gas tank. Simply replacing it got the car running.

I have seen that, but that's different from what statsman1982 brought up. Debris in the tank can clog the in-tank fuel strainer attached to the fuel pick-up tube, and it can clog the external (to the tank) fuel filter. What was being discussed, which I have not seen, is the debris lying on the bottom of the tank suddenly getting sucked in en masse when the fuel level gets low enough to run out of gas.

[Gary T]

Originally Posted by Jormungandr

On the first episode of "Mythbusters," they bought a 1967 Chevy (for the Jet Assisted Take Off Car myth) which suddenly stopped running. The reason, the fuel filter was clogged by rust from the gas tank.

Taking off on a tangent here, this situation sometimes occurs in 20+ year old vehicles with steel gas tanks. The inside of the tank is coated to prevent rust, but given enough time the coating can disintegrate. Rust formation is then rapid and prolific, and simply replacing filters and strainers only provides temporary respite. The long-term cure is to replace the tank or have it recoated.

[JFLuvly]

The fuel pump for my truck is $300.00 plus tax and that includes my NAPA discount for buying alot from them and the owner is a friend of mine. I would guess close to $400.00 taxes in for someone off the street, add in the labour to drop and drain the tank, install a new filter and pump and a grand does not seem to be all that much. Just getting the bolts out that hold the tank straps can be a pain in the butt not to mention the ring that holds the pump in on the top of the tank. Keep in mind that these things generally get pretty rusty and using a torch to loosen them is not an option.

[Qwakkeddup]

1998 Chevy 1500, first fuel pump cost ~$430.00, Kept having to exchange it under warranty.

The last time, took it to the local mechanic and spent ~$500.00 to install the warranty fuel pump, new fuel filter and the replacement wiring harness I bought for the fuel pump.

It is a little easier on a truck, you take the bed off instead of the tank, most cars require you to drop the tank and pull it out from under the car.

My 95 Jimmy cost ~$500.00 to pull the leaky old fuel tank and install the new one I had bought for it. Just in labor.

Simply, the newer fuel injection pumps are expensive on top of a labor intensive job. If the shop got your fuel pump, filter, and cleaned the injectors (for real) and installed it all for ~$1000.00 or less, I would say you got a heckuva deal.

[groman]

Originally Posted by Zsofia

The boyfriend was driving down to Charleston and the car just, you know, stopped running. (Because it was out of fuel.) The fuel gauge had stopped at a quarter tank or something and he hadn't noticed. So that broke first, and then he drove it completely out of gas.

The reason I asked is that I've driven several different cars completely out of gas multiple times and it never even occurred to me that it would cause a permanent problem. In my experience, you just push the car to a gas station, or bring some gas in a canister and it runs again. So are some peoples cars not restarting after this, or does the damage surface some time after? If so, how do people link it to the original incident of running out of gas?

[Qwakkeddup]

Older cars never seemed to have this problem, older being late 80's I think.
Once you get into fuel injection, where you are using higher pressure the fuel pumps need the fuel to keep them cooled. I believe some have safety shut off for running out of fuel. Some are just built better. Some people are just lucky/unlucky. I never ran my truck out of gas, the fuel pump just quit, the second, third, and fourth did the same. I only paid for one due to the warranty, they just didn't outlast it. Chevy was evidently known for it.

[Rick]

To the best of my knowledge all electric fuel pumps used on fuel injected cars have a cut out for when the car stalls. This is a very needed safety feature.
Picture if you will, a car crash, a fuel line gets broken, the engine stalls and the pump keeps running as long as the key is on.
Look up both
A very bad thing
and
Gigantic freakin law suit
in the dictionary. It will say: Definition A: Broken fuel line and a fuel pump that is still running. See also Big assed fire.

So what happens in the real world is: Engine stalls. Pump stops. Pump runs while engine is in crank mode (but frankly this is only for a few seconds at a time, not minutes, hours or days)

What has not been mentioned is as the engine runs out of gas, the engine misfires. As the engine misfires it can easily damage the converter under the car. A missfire will dump raw fuel into the converter. Add oxygen and it will burn and can easily get so hot, the ceramic substrate melts. Or you can get a load of raw gas into it that can explode blowing the substrate into pieces. depending on the car a converter can easily cost a G or more.

[Like Fry]

This talk of pumps being cooled by fuel brings up something Ive been wondering about for a while now.

Subaru makes upside down U shaped gas tanks with two pumps, one in each side (the U goes over the drive shaft as the tank sits in front of the rear axle). Now one of the pumps moves fuel to the engine, the other only delivers fuel to the other side of the tank.

http://www.drive.subaru.com/Sum03_FuelSystem.htm

Wouldnt that mean that the feeder side of the tank could go empty pretty easily which would mean the pump would go dry?

[Gary T]

Originally Posted by Like Fry

This talk of pumps being cooled by fuel brings up something Ive been wondering about for a while now.

Subaru makes upside down U shaped gas tanks with two pumps, one in each side (the U goes over the drive shaft as the tank sits in front of the rear axle). Now one of the pumps moves fuel to the engine, the other only delivers fuel to the other side of the tank.

http://www.drive.subaru.com/Sum03_FuelSystem.htm

Wouldnt that mean that the feeder side of the tank could go empty pretty easily which would mean the pump would go dry?

Look carefully at the diagram you linked and you'll see there's only actual (electric) fuel pump. Furthermore, the other pump, called a jet pump or transfer pump, is on the same side as the fuel pump, although its pickup tube is on the other side. The jet pump has no moving parts, and uses the momentum of fuel returning from the pressure regulator to create a vacuum in its pickup tube (the venturi effect) and thus bring fuel over to the right side. It will not be harmed by having the left side of the tank run dry.

[Gary T]

Arggh! I left out a word. My first sentence should read "...there's only one actual (electric) fuel pump."

[md2000]

Originally Posted by Rick

To the best of my knowledge all electric fuel pumps used on fuel injected cars have a cut out for when the car stalls. This is a very needed safety feature.
Picture if you will, a car crash, a fuel line gets broken, the engine stalls and the pump keeps running as long as the key is on.
Look up both
A very bad thing
and
Gigantic freakin law suit
in the dictionary. It will say: Definition A: Broken fuel line and a fuel pump that is still running. See also Big assed fire.

So what happens in the real world is: Engine stalls. Pump stops. Pump runs while engine is in crank mode (but frankly this is only for a few seconds at a time, not minutes, hours or days)

What has not been mentioned is as the engine runs out of gas, the engine misfires. As the engine misfires it can easily damage the converter under the car. A missfire will dump raw fuel into the converter. Add oxygen and it will burn and can easily get so hot, the ceramic substrate melts. Or you can get a load of raw gas into it that can explode blowing the substrate into pieces. depending on the car a converter can easily cost a G or more.

Many years ago a goofball I worked with described a trick they learned - while driving down the road, turn off the ignition for a second or two then turn it back on. Large bang! They did this once in a tunnel while passing a pedestrian and he swears she jumped 2 feet in the air. Never did say what happened to the muffler, but by this time it probably didn't matter...

[Any Other Name]

Originally Posted by Zsofia

I had a very expensive repair when my fuel gauge died and my boyfriend ran out of gas in my car. The problem was that fuel stuff cooling issue, all sorts of assemblies had to be replaced, and it cost me a thousand bucks before the day was done. In Charleston. Which is not where I live.

Ran out of gas in my car the same way. Unconvinced that I could be out of gas, I tried starting the car several times. Finally giving up, I got two gallons of gas, put it in the car, and tried again. Still nothing. Listened at the fuel fill, no pump running.

My mechanic said the pump is cooled by the fuel, cranking repeatedly would overheat the pump and shut it down. Tried the next morning, heard the pump operating, and started fine.

Definitely was out of gas, took the full capacity of the tank.

Not sure if there's an actual thermal shutdown in the pump, or if it just overheated and ran again when cooled off.

Did it again last week Fortunately, it was so cold out, it cooled off quickly.

Knowing this about my car, I doubt other cars might burn out the pump instead; running out of gas isn't uncommon. And I doubt even more that the injectors could be damaged.

But as for the cost of the repair, according to my mechanic, if I'd had to replace the pump, it would have cost over $300 for the pump and another $300 in labor. Not far from the $1000 quoted by the OP.

[Ionizer]

Originally Posted by Any Other Name

...//snip
Knowing this about my car, I doubt other cars might burn out the pump instead; running out of gas isn't uncommon. And I doubt even more that the injectors could be damaged.

Just a little 'cite' from a fuel pump maker that running out of fuel can destroy the fuel pump ->"Don’t make a habit of driving with a nearly empty gas tank. Running out of gas is not only inconvenient, it can burn up your fuel pump since the pump relies on the gas flowing through it to cool it."

http://www.carterfueldelivery.com/fu.../consumers.php

Of course, that is only one maker of fuel pumps, and there are likely other types that are not as such. But why chance it?! I'm in the habit of presuming that when a quarter-tank is indicated, its time to refuel. In my son/wife's case, she *knew* truck was almost out of fuel, had the $ for fuel specifically in pocket as she drove past the convenience-store, but she was simply too lazy...assumed that she could squeak out another thirty or so miles home then back-to-town when hubby got home so *he* could do that awful chore of fueling the vehicle.