are there any cases of a fuel level sender going out? i filled my tank the other day and drove 35 miles home, gauge never moved (normal). i drive to chiropractor this morning, around 15 miles, still hardly any movement (still normal). i leave there and head back out 35 miles and gauge shows between full and 3/4 mark (still not a problem).

i then leave and see the gauge is near 3/4 mark, so i check how many miles ive driven. i went 90 miles, which 3/4 at 90 miles has never happened. so i look for gas leak as i then notice the gauge then go closer to 1/2 mark. that the rate it moved, i was getting like 2 miles per gallon so i think that i have a serious gas leak. yet i look around and see nothing, and then check fuel range and its near 400 miles.

shortly after that, the gauge slowly goes back to 3/4. eventually it stopped just barely above 3/4 and i have like 120-130 miles on it so i wasnt concerned. but still, im near 15,000 miles and my fuel level sender (i dont think its the gauge) is going bad? but one thing i have to note is, i added an octane booster and fuel system treatment. i have used the fuel treatment before i went to florida, and this problem didnt happen. so maybe the octane booster had something to do with it? i think thats strange but im unsure.

i dont think that the octane booster did it. I think that it is your sending unit in ur tank. ur car is still under warrenty i would take it to them and let them deal with it.

thats what i figured but it happened right after i put the crap in. so it just makes you think. as of right now, it seems to be working fine again. but ill give it another tank of gas to see what happens.

Any update on this? I have had a problem with mine for awhile. I filled up and it never showed full but by the time i got were i was going it was on empty. But really i wasn't because i stop to get gas to see how much i could put in there and it was only like a little bit so i knew i had plenty of gas in there. But it does it sometimes and sometimes it doesn't do it at all.

GM has a revised program for the fuel gage problems. We have never done one here yet. But my black balt is doing what this bulletin is refering to. I might have to do it on mine to see what it takes and if it actually works.

Here's the bulletin:

Document ID# 1861088
2007 Chevrolet Cobalt


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Subject: Inaccurate Fuel Gauge Readings, Fuel Gauge Reads Empty When There is Fuel in Tank, Low Fuel Message Displayed in DIC, DTC P0461 Set (Reprogram ECM) #06-08-49-018 - (09/08/2006)



Models: 2007 Chevrolet Cobalt, HHR

2007 Pontiac G5

2007 Saturn ION


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Condition
Some customers may comment that the fuel gauge reads empty when there is fuel in the tank. Also, the driver information center may display the "Low Fuel" message.

Upon investigation, the technician may find DTC P0461 set.

Correction
First confirm that DTC P0461 has set and that no other fuel-related codes exist. If other codes are present, follow published DTC diagnostics in SI.

A new software has been developed to correct this condition. Technicians are to reprogram the ECM/PCM/VCM using SPS. The new service calibration is currently available on TIS2WEB.

Warranty Information
For vehicles repaired under warranty, use:

Labor Op--- Description -------------------------------------------------------Labor Time

L1199* -----Reprogram ECM to Correct Fuel Gauge Issues Using SPS ---0.4 hr

* This is a unique labor operation number for bulletin use only. This number will not be published in the Labor Time Guide.

how big is the tank and at what point SHOULD the low fuel light come on?
if it makes any difference, i am referring to my 07 ss/sc

i reprogramed my ecm at work and it still does it, i checked the voltage on the fuel level sensor and its a constant voltage. so the sensor isnt bad but i dont know =\, i dont really want to diagnose my own car because that takes away from money i could make

how big is the tank and at what point SHOULD the low fuel light come on?
if it makes any difference, i am referring to my 07 ss/sc

about when 2 gallons are left and the tank holds 13.** gallons

Any other news on this? I have a 2006 so I'm not sure if that applies to me up there --^ but I am starting to have the same problem.

I will fill up and teh fuel gauge won't go up right away, sometimes for a while. And when it does go up, it goes up really really slow.

Any ideas?

Any other news on this? I have a 2006 so I'm not sure if that applies to me up there --^ but I am starting to have the same problem.

I will fill up and teh fuel gauge won't go up right away, sometimes for a while. And when it does go up, it goes up really really slow.

Any ideas?

do you leave your car runnning when you get gas, if so that doesnt read correctly like that, but if you dont then id say your fuel level sensor causing that

No, car is off when I fill up.

Same problem here. I will fill up and car will not read full when I start back. And my needle kinda moves alot. I have a heavy foot, but this is outside of normal for heavy driving.

The gas hand reads 7/8'ths at fill up.

i have 06 ss n/a and i have my check engine light keep coming on and it says fuel regulator or something like that but no warranty so i am going to have to pay :( my cobaltt sucks

My car has the fast moving fuel gauge. Needle goes all the way to Full and within 20-30 miles the gauge is already near inbetween F-3/4. Took it to the dealer, in reference to the TSB and found my sending unit was bad. 2 were found originally and after waiting a week the part shows up and gets installed. No less than 24 hrs later...CEL and no fuel pressure. The part sent was faulty. Now I'm told the part has been ordered AGAIN yet the time frame to get it is undetermined.

mine is extremely jacked... ive driven 150 miles and im at 1/4 tank.... makes no sense