Full tank of gas, but the low fuel and indicator??

[powayroger]

I have a 01 Chevy Silverado (I’m the original owner) 2wd 4.8 liter auto. I have 94,000 on it (Low mileage due to buying a Honda civic for daily 81 mile commute 3.5 years ago. 18 mpg vs 40 mpg? Well, you know which one I drive the most now.). I maintain my vehicles well and normally don’t get rid of them until after they hit the 150,000 mile mark.

So I just got back from this trip from San Diego County up Hwy 395 into the eastern Sierras (As far north as Mono Lake). After getting my first refuel at Lone Pine (now a full tank, purchased at Mobil, where I get most of my gas) and heading back onto 395, all of a sudden, my low fuel light went on and my fuel indicator moved to E. It stayed there for about 10 seconds (As I started pulling over to the side of the road, think I might have somehow cut my fuel line) and then reset itself. So I started down the roadway again and about 10 minutes later, it did the same think. I pulled over in the rest area and disconnected the battery, waited for a few minutes (I’m think something in the computer needs resetting because of the elevation, maybe), reconnected, and no more problems for the rest of the day. Next day, problem started again, and today, same problem (And no I did not disconnect the battery).
At no time, when the low fuel light and indicator needle fell to E did I experience any hesitation (like running out of gas). Truck performed normally.
Before I take it down to the dealer to get checked out, has anyone else experience this problem before and if so, what was the cause?

I’m thinking it could be a solenoid or a relay going out. What about a sign that the fuel pump is on its way out? I have the original pump (I Had an 85 S-10 Blazer in which the fuel pump went out at the 75,000 and 150,000 mile marks).


Thanks for your help.

 

[Warstud]

Sounds like a Bad Sending Unit. I think some people have had good luck running MMO in the tank. Seems to clean the SU and make it function properly again. Otherwise you probably have to replace the fuel pump because the SU is attached to it.

 

[powayroger]

I always use MMO. Maybe that is why the pump has lasted so long.

 

[mikered30]

Try 2 bottles of Techron in the gas.

 

[AstroTurf]

Run a can of GM Part number 88861011.

It is their fuel system cleaner which also cleans the sulfur off of the fuel gauge sending unit.

Hope this helps, Jim

 

[SrDriver]

Originally Posted By: mikered30
Try 2 bottles of Techron in the gas.


+1 on the Two bottles of Techron. Pour it in then top off with gasoline and run the tank until about empty.

 

[powayroger]

Before I left on the trip, Chevron was actually cheaper than mobil, so I filled up my tank at Chevron. I would say 95% of fillups are at teh local mobil and I do put in a can of b-12 every 3,000 miles, along with MMO at 1000 miles.

 

[snapcrackle12]

As a tech I can tell you it is either in the cluster module, fuel level sending unit which is common on gm. Also could be in wiring. Additives and brand of fuel have nothing to do with it.

 

[AstroTurf]

Originally Posted By: snapcrackle12
As a tech

tech of what?
Originally Posted By: snapcrackle12
I can tell you it is either in the cluster module, fuel level sending unit which is common on gm. Also could be in wiring.

What about the TSB that GM put out on this problem, and their fix... part# 88861011
Originally Posted By: snapcrackle12
Additives and brand of fuel have nothing to do with it.

You are on a roll... The quality of fuel and treatments have everything to do with the delicate fuel sending unit.

Thanks, Jim

PS part# 88861011... It Works.

 

[daman]

Our '01 2500 6.0 just had this problem last week..

sending unit...

 

[Patman]

That's a common problem on the 97-04 Corvettes too, and most people have solved it with fuel injector cleaner, as it helps clean the sending unit. I used to have that problem about once a month (and the gauge would fix itself on the next restart) in the first couple of years that I owned my Corvette, but mysteriously the problem just went away on it's own and it hasn't occurred again in at least 4 years.

 

[GMBoy]

Originally Posted By: AstroTurf
Originally Posted By: snapcrackle12
As a tech

tech of what?
Originally Posted By: snapcrackle12
I can tell you it is either in the cluster module, fuel level sending unit which is common on gm. Also could be in wiring.

What about the TSB that GM put out on this problem, and their fix... part# 88861011
Originally Posted By: snapcrackle12
Additives and brand of fuel have nothing to do with it.

You are on a roll... The quality of fuel and treatments have everything to do with the delicate fuel sending unit.

Thanks, Jim

PS part# 88861011... It Works.



You beat me, and you said it all. GM recommends their cleaner or Techron in the bulletin and I have personally seem SEVERAL cars/trucks have their fuel gauge issues solved by using the additives. Some gas does have too much sulphur and that hurts the sending units.

 

[GMBoy]

Originally Posted By: daman
Our '01 2500 6.0 just had this problem last week..

sending unit...



Should have used Techron first before spending the money. I've done this on Vettes, Trucks and even an HHR. Worked.

 

[daman]

Originally Posted By: GMBoy
Originally Posted By: daman
Our '01 2500 6.0 just had this problem last week..

sending unit...



Should have used Techron first before spending the money. I've done this on Vettes, Trucks and even an HHR. Worked.

Wasn't the problem, the coil and the pivot arm were shot(slop),no additive would have help. It lasted over 200k so no sweat there..

 

[Rand]

Had a bad ground do that on my thunderbird..

the mystery go to E or F i forget.
its been a few years.

 

[oldmaninsc]

Originally Posted By: snapcrackle12
As a tech I can tell you it is either in the cluster module, fuel level sending unit which is common on gm. Also could be in wiring. Additives and brand of fuel have nothing to do with it.

I had this problem on my Trailblazer at about the 5 year/ 60K mile mark. I tried several cleaners (MMO, Techron, Seafoam) and none fixed the problem. I normally used Chevron gasoline in it - occasionally Shell. As a matter of fact the day it started doing this was when I filled up at my local Shell station.
Most of us over at Trailvoy.com found it to be the fuel gauge sending unit in the tank. The few that said the fuel additives DID work for them, found out it was only temporary and eventually ended up replacing the sending unit like the rest of us.

 

[powayroger]

I got a GM "Value guard" protection plan which expires in November (Got it from GM many years ago when I threaten to make one issue into a lemon). I might as well use it since it seems covered. For teh most part, my silverado has been a great truck.

 

[snapcrackle12]

Originally Posted By: GMBoy
Originally Posted By: AstroTurf
Originally Posted By: snapcrackle12
As a tech

tech of what?
Originally Posted By: snapcrackle12
I can tell you it is either in the cluster module, fuel level sending unit which is common on gm. Also could be in wiring.

What about the TSB that GM put out on this problem, and their fix... part# 88861011
Originally Posted By: snapcrackle12
Additives and brand of fuel have nothing to do with it.

You are on a roll... The quality of fuel and treatments have everything to do with the delicate fuel sending unit.

Thanks, Jim

PS part# 88861011... It Works.



You beat me, and you said it all. GM recommends their cleaner or Techron in the bulletin and I have personally seem SEVERAL cars/trucks have their fuel gauge issues solved by using the additives. Some gas does have too much sulphur and that hurts the sending units.


Granted very rarely that works. So when that doesn't work then what do you do? Put another bottle in and cross your fingers, or actually diagnose it instead of throwing parts at it. Because 9 out of 10 usually the fuel level sending unit has failed other times wiring or cluster module. Sounds like you work for the dealer. Keep charging the customer until its fixed!!!! Fix it right the first time.

 

[ComfyShorts]

Originally Posted By: snapcrackle12

Granted very rarely that works. So when that doesn't work then what do you do? Put another bottle in and cross your fingers, or actually diagnose it instead of throwing parts at it. Because 9 out of 10 usually the fuel level sending unit has failed other times wiring or cluster module. Sounds like you work for the dealer. Keep charging the customer until its fixed!!!! Fix it right the first time.



Oh snap!

 

[AstroTurf]

Originally Posted By: snapcrackle12

Granted very rarely that works. So when that doesn't work then what do you do? Put another bottle in and cross your fingers, or actually diagnose it instead of throwing parts at it. Because 9 out of 10 usually the fuel level sending unit has failed other times wiring or cluster module. Sounds like you work for the dealer. Keep charging the customer until its fixed!!!! Fix it right the first time.


Actually, It sounds as though you might be a tech at Pep Boys...

You see it is that 1 out of 10 that you have found it to be something else that concerns me.

Good Luck in your tech-hood, Jim

EDIT: PS How do you diagnose sulfur on the sending unit?