Diesel Place banner
1 - 11 of 11 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 ·
Hello All, My first question post, have learned quite a bit on here, so I am hoping someone can explain. I just filled my truck for the first time Fri. I was unsure how fast the gauge went to empty once it got to a 1/8 of a tank, so I filled up. I put in 33.4 gallons, I have a single 40 Gallon tank option (NH4) and a factory option extra 15 gallon add on (NXN). To me that adds up to 55 gallons. When I first started driving the gauge said 1/2 full, 5 minuets later it was at 7/8 full and 2 minuets later at was at a needle width past the full mark. Full is full right? Anyway I then went under the truck to find a label on the single and only tank that said 53 US gallons. It also said not to fill it with more than 95% liquid. So whit my calculations that is about 50 gallons. So finally my question, where is the GAS? I would not expect the gauge to read 1/8 full and still have 16.6 gallons in the tank. I also would think because it said full that it is not 16.6 gallons short of full. Please help?

:banghead:

Thanks,

Eric

Need to add my sig! 2006 C4500 regular cab 2wd Duramax 6.6 Diesel (LPD)
 

Attachments

·
Registered
Joined
·
3,129 Posts
The only thing that comes to mind is if I leave my DM running when I'm fueling up,the gauge will act wacky for a few hours and then will straighten out.You said gas in your post--bad choice of word because I would'nt want you to screw up at the pump.
 

·
Registered
Joined
·
178 Posts
The same thing happens with the Isuzus we have at work. For a minute they read empty and then gradually go to full. I was told it just takes a while to register with the trucks and isnt anything to worry about. On the gauge reading 1/8th of the way full with 16 gallons could the bottom of your tank be bigger than the top half? On my truck the top half is about 22 gallons and the bottom twelve. So when it read half full I fill with around 22 gallons and once you reach the bottom half of the tank the fuel will disapear alot quicker
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #4 ·
[email protected];1545965; said:
The only thing that comes to mind is if I leave my DM running when I'm fueling up,the guage will act wacky for a few hours and then will straighten out.You said gas in your post--bad choice of word because I wouldn't want you to screw up at the pump.
Your right "GAS" is a bad word, Fuel is the word to use, but I always say "I'm going to the gas station, or I need gas, not fuel or fuel station." Something I need to work on now that I finally own a Diesel! I did leave the truck running while I filled up, and the gauge did act weird, which I find normal since it does it with all of my other vehicles also. But I was hoping the pump shut off prematurely, maybe because the body company did not put enough tilt in the fill spout. Then when the Gauge showed full I was confused! I was hoping someone would read this post with the same tank setup and let me know that 1/8 full still gets them 128 or so miles (16 gallonsX8mpg=128) I just don't think this sounds possible. Would like to run it dry to find out for sure, but I'm pretty sure that would be a DUMB move!, and guess would cause some sort of damage? :eek: I bought a set of service manuals with the truck, but no luck with them yet, actually you need a manual to help you navigate the manuals. :help2:
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #5 ·
921500Z71;1546388; said:
The same thing happens with the Isuzus we have at work. For a minute they read empty and then gradually go to full. I was told it just takes a while to register with the trucks and isnt anything to worry about. On the gauge reading 1/8th of the way full with 16 gallons could the bottom of your tank be bigger than the top half? On my truck the top half is about 22 gallons and the bottom twelve. So when it read half full I fill with around 22 gallons and once you reach the bottom half of the tank the fuel will disapear alot quicker
What is you total tank size in gallons? Am aware of the slowness of the gauge, but when it read full at the end of my 10 miunet or so trip I was confused. If I was only a gallon or so short I would not even question it, but 16.6 gallons :wtf1: .
 

·
Registered
Joined
·
3,129 Posts
I'm confused by your tank situation from your first post.Do you have 1 or 2 tanks?On my 7500 Chevy,I have dual 50 gal. tanks.The manual advises I fill the driver's side first for the most accurate fuel reading.Sometimes I can't and then it takes a long time for an accurate read.This might be your situation.Also,I had that level fill hose on a service body on my first '01 2500 DM--it really sucked--had to fill very slow. I think if it had more venting, it would be fine.
 

·
Registered
Joined
·
255 Posts
its very easy. the nh4 is a 40 gal fuel tank. the NXN option code is an option for gm to add 15 gals of fuel to the truck before it is delivered to the dealer. You only have a single tank. Check with your salesperson if he can show it to you
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #8 ·
[email protected];1547041; said:
I'm confused by your tank situation from your first post.Do you have 1 or 2 tanks?On my 7500 Chevy,I have dual 50 gal. tanks.The manual advises I fill the driver's side first for the most accurate fuel reading.Sometimes I can't and then it takes a long time for an accurate read.This might be your situation.Also,I had that level fill hose on a service body on my first '01 2500 DM--it really sucked--had to fill very slow. I think if it had more venting, it would be fine.
I have (1) tank that is shown in the attachment photo, it has a sticker on it that says 53 US Gallons. As for the level of the fill hose I did not have any problems with the pump shutting off during filling, unless it shut off with the 33.4 gallons when it should have kept going? But again the gauge shows full, that is why I started this post. Thanks for the reply though!
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #9 ·
northwood;1547131; said:
its very easy. the nh4 is a 40 gal fuel tank. the NXN option code is an option for gm to add 15 gals of fuel to the truck before it is delivered to the dealer. You only have a single tank. Check with your salesperson if he can show it to you
I am aware of my single tank, it is shown in one of my posts as a photo. That single tank however has a MFG. sticker on the tank that says 53 US Gallons, and not to exceed 95% of liquid capacity. This is where my confusion is! If I paid for the MFG. to put 15 gallons of fuel in the tank, than that makes no sense with the sticker on the tank. I have the cut sheet from the order and (NXN) is "FUEL-ADDITIONAL 15 GALLONS (56.7L) - added at the assembly plant (N/A with NK1 single and NG6 dual fuel tanks)." It also shows added weight to the truck of 121.25 pounds to the rear. Just for sake of argument 40 Gallons + 15 gallons = 55 gallons 95% liquid capacity = 52.25 US gallons, makes sense to me. But where is it? Also if I paid for the extra fuel to be put into the tank on the invoice I guess the dealer saved 15 gallons of fuel upon delivery, since they fill the tank for you free before you leave.:mad: !!!!!!
 

·
Registered
Joined
·
3,129 Posts
I think you simply have a faulty gauge.After documenting some more fill-ups--show your dealer your info if it still makes no sense.Nice truck-nice wire job---I'm guessing you have that truck because you're an electrician.
 

·
Registered
Joined
·
9 Posts
Would like to run it dry to find out for sure, but I'm pretty sure that would be a DUMB move!, and guess would cause some sort of damage?
yes it wouldnt be to great of an idea. the mfg. puts the fuel pump in the tank for multiple reasons. one of them being it is a pump, it has a motor, so it will get hot. the fuel is used to cool the fuel pump and keep it from burning up, thus extending the life. plus you dont want pump any air through the fuel lines.

my guess is that sending unit for the fuel gauge isnt the right one for that fuel tank option

mike
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top