Fuel Gauge Issue - Apparently I Have a 26 Gallon Tank?

[mals]

So, I was just looking through the forums and saw a thread about the possibility of installing a 37 gallon tank from a 2500 into a Yukon. That peaked my interest because for the past few months that I've owned it the one complaint I've had about my Yukon is the small fuel tank and limited range.

In reading that thread I quickly realized that the standard tank in the Tahoe/Yukon 1500 is 26 gallons. I've been working on the assumption that I had an approximately 16-17 fuel gallon tank based on my observed usage. When I drive my Yukon until the gauge is on empty, and the calculated range is around 50 miles, I fuel up. Looking through my log my fill ups have ranged from 14.5 gallons to 15.6.

I don't think it is the stepper motor in the gauge since the trip computer also thinks the tank is nearly empty. Is this a typical symptom of a bad sending unit? I'm excited to learn that I suddenly have 10 gallons more capacity since I primarily use the Yukon for towing, but I'd like to straighten out the gauge reading so I can confidently use my new extended range.

 

[retiredsparky]

I think that your experience is common with these 26 gallon fuel tanks. Most manufacturers deliberately mislead us to make sure there is enough fuel to cool the fuel pump. For some reason, empty on the gauge is about 20 gallons used out of 26. So your gauge is off even more if you are filling up on "E" or close to it and only putting in 15.

A little known part in the fuel tank that affects amount of fuel into the tank is the vent tube. On some vehicles, Ford F-250's for example, the vent tube is extremely low in the tank, so trimming the vent tube allows extra fuel to be pumped into the tank. Your experience might be related to this or not!

 

[mals]

I think that your experience is common with these 26 gallon fuel tanks.... For some reason, empty on the gauge is about 20 gallons used out of 26.

Thanks for the ideas. Just to double check I went to fuelly.com and browsed other 2005 Yukon owners fuel logs. Looks like most users largest fill ups are around 22-23 gallons, and a few brave owners push it to 24.

After more research, I am leaning to it being an issue with the fuel pump sending unit. My only hesitation is that most fail and only read full, or empty, or give eradicate readings. When the sender in my Astro failed it read fine for the top of the tank, then eradicate for the bottom half. My Yukon seems to read fine for the fuel range from F to E, just poorly calibrated.

I'd hate to drop the tank, install a new fuel pump only to have the same issue. I guess the worse case I get a new fuel pump out of it and eliminate it as the cause.

 

[mitchn06]

Thanks for the ideas. Just to double check I went to fuelly.com and browsed other 2005 Yukon owners fuel logs. Looks like most users largest fill ups are around 22-23 gallons, and a few brave owners push it to 24.

After more research, I am leaning to it being an issue with the fuel pump sending unit. My only hesitation is that most fail and only read full, or empty, or give eradicate readings. When the sender in my Astro failed it read fine for the top of the tank, then eradicate for the bottom half. My Yukon seems to read fine for the fuel range from F to E, just poorly calibrated.

I'd hate to drop the tank, install a new fuel pump only to have the same issue. I guess the worse case I get a new fuel pump out of it and eliminate it as the cause.

So did you do it? I seemingly have the same issue. I think my last fill was 15-16 gallons and I was certain it should have been 20 or more. I'll let you be the guinea pig.


Sent from my iPhone using Tapatalk

 

[mals]

So did you do it?

No, not yet. I've been driving it this way for 6 months, so it's not really a pressing issue. I will likely tackle dropping the tank and replacing the fuel pump in the spring when it will be a little more pleasant to lay on my back in my driveway.

 

[SnowDrifter]

The 2500 has the long wheelbase yeah? I'm not sure it would fit. The fuel tank is a lot longer

 

[mals]

The 2500 has the long wheelbase yeah? I'm not sure it would fit. The fuel tank is a lot longer

Oh, I have no interest in installing a larger tank. I was only referencing that thread since it was what tipped me off that the standard tank size is 26 gallons when I had assumed through experience that it was around 16.

 

[SnowDrifter]

Ahh gotcha. Does yours have the information display that tells you how many gallons of fuel you've used?

I generally fill up about 1/3 tank on mine


Edit: Yours is 2005. Don't quote but but I think it does

 

[mals]

Ahh gotcha. Does yours have the information display that tells you how many gallons of fuel you've used?

The only gallon totals I've seen in the information display is in the main vehicle information menu; Total Odometer, Total Engine Hours, Total Gallons Used, and Avg Fuel Economy. My total fuel used is pegged at 9999.99 with an average fuel economy of 12.5. That makes sense to me because 158,000 miles at 12.5 MPG is 12,640 gallons, but seems odd that GM wouldn't see the need to account for more than 10,000 gallons of fuel used over a lifetime.

I've seen no menu items for per tank gallon consumption totals or instantaneous fuel consumption, just projected mile range of tank remaining. If I am missing something obvious in the information center, let me know.

Is there any way to reset the Fuel Total and Average Fuel Economy? I've kept track of that information using Fuelly.com since I purchased the Yukon, but it would be nice to have useful information in the display center.

 

[SnowDrifter]

You can reset the gallons used thing. I reset that when I fill up. You should be able to reset them both by pressing and holding the arrow on the lower right of the steering wheel controls


If you have access to a scan tool you can also view the observed/commanded fuel levels