Faulty Fuel Gauge?

[Irv]

Filled the truck this morn and it showed full on the gauge after I left the gas station, get to work and happen to glance down and notice it only show 1/2 full

 

Tonight when I left work, it showed low, enough to highlight the gas sign so I checked my DIC milage range and it only said 28 Km range?

I checked under the truck looking for a puddle of gas and none was found and there was zero smell?

 

Left for home and as I am driving the gas guage slowly starts to rise up, it got to just over a half tank showing as I pulled in the drive?

 

Any idea(s) what is going on?

If the 2 are related, I have noticed quite a change(for the worse) in my gas milage the last month but put it off as colder weather, snow tires, city driving etc?

[cerbomark]

that happened on my NBS 07 when it got cold outside. Something with the cold I remember. When I usually shut it and restarted the truck it went back to were it should be. I think there was a TBS but can t remember. Someone will remember and post it.

[Zembonez]

I also heard that this was a cold weather issue. Somebody last year here was having it. I do believe there was a cold weather areas TSB on it. Hopefully somebody will chime in here or a call to your local dealer might do the trick.

[cerbomark]

do a search in the 2007/08 time frame under fuel guage.

[cbrown4390]

were you parked on an angled driveway

[Erichcb]

that happened on my NBS 07 when it got cold outside. Something with the cold I remember. When I usually shut it and restarted the truck it went back to were it should be. I think there was a TBS but can t remember. Someone will remember and post it.

 

You are right there is a TBS out about this...I had my fixed on my truck shortly after I got it....Here ya go bud....

 

Its not a recall,But a bulletin.....

 

 

Document ID# 1966877

 

 

 

Subject: Fuel Gauge Erratic In Freezing Temperatures P0463 - keywords cluster cold float gage inaccurate intermittent IPC level sender #PIT4294C - (04/30/2007)

 

 

 

Models:

2007 Chevrolet Silverado

 

2007 GMC Sierra

 

With One Of The Following Engine RPO's: L76, LC9, LH6, LMG, LY2, LY5, or LY6

 

 

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

 

Condition/Concern:

The fuel gauge erratic and displays the incorrect fuel level in freezing weather.

 

Example concerns:

The fuel tank is ¾ full. While driving, the fuel gauge gradually starts to display a lower fuel level, beyond the reduction that is due to engine fuel consumption. The fuel gauge may subsequently recover to an accurate fuel level display.

After being parked in below-freezing weather, the vehicle is started and the fuel gauge displays a reading of "E". With driving, the gauge reading may slowly recover towards the actual fuel level. If the ignition is then cycled, the fuel gauge may now display the actual fuel level.

Note: A P0463 Diagnostic Trouble Code may or may not be set. If it is set, the fuel gauge is commanded to "E".

 

The condition is related to excess water in non-ethanol fuel at below-freezing temperatures causing ice crystals in the fuel which interfere with the proper operation of the fuel level sender.

 

Recommendation/Instructions:

To correct this concern replace the fuel level sensor kit with part numbers 19168425, 19168426, or 19177140, depending upon your application. See your parts department for correct part.

 

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

 

© Copyright General Motors Corporation. All Rights Reserved.

[STINSAN3]

were you parked on an angled driveway

 

I hate this the most : (

If your on low level, then it goes verrrrrrry low

[peterupnorth]

Had the same thing happen several times up here in -40. (Also crawled under to check for leaking tank...)

Dealer knew all about it. Said he could fix it, though meant a 3+ hour repair to pull the tank (on warranty).

Even at cold temps, it generally goes away after about an hour of driving.

Told him not to bother.

 

Maybe a slurp of quality gas line antifreeze in the fuel once in awhile would prevent this altogether.

[BKfirefighter3221]

GM has had a huge problem with their fuel gauge in tank senders ever since they went to the "module" pump design in the mid 90's. The trucks started in the late 90's and I have seen it pretty regularly when they reach around 100,000 miles. A Delphi instructor told me that they knew the material would not hold up for the long term in fuel but GM told them not to change the design. Now it sounds like they are having an even bigger problem with the newer ones.

[jhm]

GM has had a huge problem with their fuel gauge in tank senders ever since they went to the "module" pump design in the mid 90's. The trucks started in the late 90's and I have seen it pretty regularly when they reach around 100,000 miles. A Delphi instructor told me that they knew the material would not hold up for the long term in fuel but GM told them not to change the design. Now it sounds like they are having an even bigger problem with the newer ones.

My '01 started giving crazy readings especially after filling up started about 65k. It drops down to empty then goes to 1/2 then to full then to empty..... I use the trip odo to backup the crap sending unit.

[BKfirefighter3221]

GM has had a huge problem with their fuel gauge in tank senders ever since they went to the "module" pump design in the mid 90's. The trucks started in the late 90's and I have seen it pretty regularly when they reach around 100,000 miles. A Delphi instructor told me that they knew the material would not hold up for the long term in fuel but GM told them not to change the design. Now it sounds like they are having an even bigger problem with the newer ones.

My '01 started giving crazy readings especially after filling up started about 65k. It drops down to empty then goes to 1/2 then to full then to empty..... I use the trip odo to backup the crap sending unit.

 

 

 

Thats the best way I think. Then when your fuel pump goes out it comes with the sender already on it.

[Irv]

Thanks for all the info guy's

 

This morning my truck was showing about half a tank(even though it initially showed almost full after yesterday's $30.00 fill up?)

 

I decided to stop and completely fill the tank up today to see what would happen,,,,it only took 26.5 Lts (about 5 CDN gallons I believe?) to go from 1/2 full to full?

 

The gauge registered full and continued to register full for the rest of the drive to work(approx 15km's) unlike it did yesterday.

I went out at lunch and went for a short drive (2-4km's) and the gas gauge never moved at all, which was completely different from yesterday.

 

The thing about this TBS is, it hasn't been very cold up here lately, only slightly above the freezing mark at +2,+3 degrees C, not even close to -10 or -20 or colder?

 

Also my truck only has 9,830 km's on it, a far cry from others on here who have had the same issue but with a lot more miles on their rigs?

The truck is going in this Friday for one more listen to my noisey engine before they decide to replace the lifters or not, so I will be sure to let them know about this wonky fuel gauge as well.

Any idea how long the TBS service will take, is it an easy fix or will it be time consuming like I suspect it will be? Anyone want to buy a truck LOL?

[michigan2500hd]

my 07 also has a major fuel gauge issue...started not long after i bought it. ran out of gas rigt after the lw fuel light came on...chaulked it up to my stupidity and thought maybe the light was on longer then i noticed it. Second time it happened it showed i had an 1/8 of a tank. Took it to the dealer who said they had to flash the sending unit and that it was fixed....third time i ran out a year later and the gauge said just a tad under 1/4. fourth time....( i know...lol..) the gauge said just over a 1/4 tank.....fifth time was a few weeks ago at 3/8 tank...called the dealership and they said its been to long since they " fixed it" and i was out of warranty. Sheesh!!

[jhm]

my 07 also has a major fuel gauge issue...started not long after i bought it. ran out of gas rigt after the lw fuel light came on...chaulked it up to my stupidity and thought maybe the light was on longer then i noticed it. Second time it happened it showed i had an 1/8 of a tank. Took it to the dealer who said they had to flash the sending unit and that it was fixed....third time i ran out a year later and the gauge said just a tad under 1/4. fourth time....( i know...lol..) the gauge said just over a 1/4 tank.....fifth time was a few weeks ago at 3/8 tank...called the dealership and they said its been to long since they " fixed it" and i was out of warranty. Sheesh!!

I remember reading here, I think, that there was a new line of fuel pumps out that did not fail like the oem do. The sending units tend to get corrosion on the contacts causing the bad readings. I remember someone saying he went thru about 4 pumps before finding the improved models. I want to search for the thread but dont have time right now, maybe call Carquest.

[ex-s/choice]

Hello everyone,

I have experienced similiar problems as well with a 2007 Sierra 1500 GMT 900 5.3 LS6 engine.

The symptoms occured while the temp is below -22 Celsius .

 

On a hunch I have used Methel hydrate to see if I could fix the problem and low and behold it seems to be working OK now.

I put in about 1.5 liters to 75liters of gas .

 

The assumtion I am thinking is that the water in the fuel is freezing to the sending unit reostate and causing the fuel gauge to recieve erronious indications. With methyl hydrate added the water /frost is reabsorbed into the fuel and the sending unit is once again working properly.....for now.

 

 

Will report agin if things should change.

 

Cheer