Gaslight

Shirley Gauthier · February 8, 2020

Hi my name is shirley, after your gaslight comes on how many miles do you have in a GMC Sierra truck.

davester · February 8, 2020

It varies both with the model/year of the truck, and then exactly how the fuel level sensor reads on each particular truck.

My truck can go at least 20 miles, but I haven't found the limit.

And you don't want to find the limit either.

Fuel pumps rely on fuel for both cooling and lubrication. When there is no fuel, the pump dies quickly.

As an example, my truck has two fuel tanks, so two fuel pumps, and the warranty for one of the pumps I put in said that the warranty was void if the pump was run for 3 seconds without fuel....

Colossus · February 9, 2020

Yup. Don't be running it below 1/4 of a tank on any car.

CamGTP · February 9, 2020

Any fuel that isn't burned my the engine is sent back into the bucket to help cool the pump and for the pick. It's really tough to burn up a fuel pump from low fuel.

Roughly 4-5 gallons of fuel is left in my truck. My normal avg for gallons is around 19-20 and the light hasn't come on yet.

davester · February 9, 2020

5 hours ago, CamGTP said:

Any fuel that isn't burned my the engine is sent back into the bucket to help cool the pump and for the pick. It's really tough to burn up a fuel pump from low fuel.

Roughly 4-5 gallons of fuel is left in my truck. My normal avg for gallons is around 19-20 and the light hasn't come on yet.

Sure, if you don't run the tank empty enough to get the low fuel warning, you won't burn up your fuel pump.

That is literally the opposite of what is being discussed.

xranger90 · February 9, 2020

On 2/9/2020 at 6:03 AM, davester said:

And you don't want to find the limit either.

Fuel pumps rely on fuel for both cooling and lubrication. When there is no fuel, the pump dies quickly.

As an example, my truck has two fuel tanks, so two fuel pumps, and the warranty for one of the pumps I put in said that the warranty was void if the pump was run for 3 seconds without fuel....

Definitely, my buddy learned the hard way and cost him a pump.

CamGTP · February 10, 2020

16 hours ago, davester said:

Sure, if you don't run the tank empty enough to get the low fuel warning, you won't burn up your fuel pump.

That is literally the opposite of what is being discussed.

How so?

She asked how long can you go when the light comes on. With mine I said I have 4-5 gallons left, then you have to do some math to figure out your distance but I didn't think I'd have to type that. If you got 20mpg, that's 80-90 miles until you're out. OR if it was 15mpg, that's only 60-70 miles until it's empty.

Even with 4-5 gallons left and the light on, you won't burn the pump out and that is WAY below the 1/4 tank mark on the fuel gauge. Maybe with 1-2 gallons left, the cooling ability will start to be far less because that little amount of fuel will heat up much quicker.

Colossus · February 10, 2020

The problem is- is that when the fuel has gotten that low, the cooling properties of any fuel that is returned is going to be extremely low, which means all it's doing is returning hot fuel. So DON'T DO IT! PERIOD!

CamGTP · February 10, 2020

We are all aware of a problem it could cause if you let it get extremely low. Nothing bad will happen with several gallons left when the light just come on. If it was truly a HUGE issue there would be shops full of cars every single day with gravy work for fuel pumps and shops would be making a killing.

Nothing wrong with filling up at 1/4 tank, knock yourself out but it's not a death sentence to the pump at that point.

dsr611 · February 11, 2020

On 2/8/2020 at 7:04 PM, Colossus said:

Yup. Don't be running it below 1/4 of a tank on any car.

Someone forgot to tell my wife that, or either the fuel tank has an air conditioner duct blowing on the pump. 300000+ miles on the original fuel pump in an 05 Tahoe and she NEVER refuels until the fuel range on the DIC shows LOW.