Sudden fuel gauge issue....

[Voymom]

My husband and I noticed on Saturday that the fuel gauge is starting to act wonky. We filled it up Thursday(full tank) and by Saturday with only driving 10 miles(5 miles to wal-mart and 5 miles back) that the fuel gauge was reading 3/4 tank full....that's not right.

Then when I made a turn, I can't remember if it was a left or right turn, the tanks gauge said full again.

Today I went down to the gas station, and when I started the truck it was a bit below 3/4 tank, it was like that the whole way to the gas station until I turned into my subdivision. I made a left hand turn into the neighborhood and it said full tank again.

This has never happened in the Envoy ever since I have owned it. I have only experienced this with one other vehicle and that was in my Buick Rendezvous. It was so bad in the Buick that we almost ran out of gas twice while out of town.

I know there is a problem with the filler neck(i think thats what its called) where it stops the gas pump prematurely, but we don't go by when the pump shuts off unless we have the appropriate amount of fuel per gallons on the gas pump itself because of this issue, so I know that the $75.00 it cost to fill up the tank was a sufficient amount.

Any idea's as to why this is now happening? What do I have to fix now?

Thanks

 

[navigator]

It is a pretty common issue with the fuel sender going bad.
Mine started similar to yours when I filled up. Then it would show empty for about 40-60 miles after filling up before correcting.
Now it shows empty all the time.

Call your local dealer, they should split the cost with you if you are under 120k miles.

 

[mike_k]

had what sounds like the same thing happen on my grand am and it ended up being the fuel level sensor on it. would show 3/4 full and ten start bouncing back and forth until it stopped on empty

 

[MAY03LT]

Any idea's as to why this is now happening? What do I have to fix now?

I don't usually see/hear of problems with the 02-03 fuel level sending units, but since the gauge is acting weird when the truck turns, I'd suspect a problem with the sending unit. Our 03s won't turn on the CEL for a sending unit fault like the newer ones do. After the preliminary tests, including stepper motor sweep and wiggle wire test, I test them by removing the pump module, hooking up a dmm (set to ohms) to the sending unit leads, and manually moving the sending unit through its range while watching the dmm. I'm 99% sure that there is a super technical min-max ohm value chart, but I don't follow it, any spikes or abnormal readings while it goes through its range calls for a sending unit.

I remember back in the day, when the 04 and ups were starting to have gauge issues, but the sending units weren't available without having to buy the whole pump module, some folks were running that seacrap or crapron through their tanks to try to dissolve any crap that may have build up on the sensor wiper thingy. Hit and miss results.

 

[Voymom]

Okay guys/gals, this is my update.

I called the local delearship, told them I needed the Fuel sending sensor, they told me to replace that in this truck I need the entire fuel tank assembly. That costs $500.00 and there is NOTHING about splitting the cost even though I am under 120k miles. The mechanic I spoke to, as he was playing the "parts" person due to the parts guy being out for the day, and he told me I only need the little floaty thing, the fuel leveling sensor...that is $158.00 and no splitting costs with that either. The dealership I bought the truck from won't even talk to me lol we had a falling out because he sent me home in a truck with no heat in the middle of winter, and I demanded that he fix the issue(which he did) and they haven't spoken to me since.

So, I'm a bit confused as I am still quite a noob and trying to learn as much as I can. I'm confused as to exactly what part I need to replace. Is it the fuel sending unit, the fuel level sensor?

The ONLY symptoms the truck has, is the premature shut off at the fuel pump, which has never been an issue for us, as we can wiggle it a bit and it fixes the issue, and it's intermittent.

NOW, The symptoms I have with the gauge, is the fuel gauge reading a certain amount of gas(3/4 tank) and on turning it brings the fuel gauge back to full. It hasn't yet bottomed out to empty YET. The DIC also shows the drop in fuel. For example, 3/4 tank adds up to 180 miles left till empty, I turn fuel gauge reads full and the DIC reads 282/300 miles till empty.

I hope that's not confusing. I also hope I don't need to replace the entire fuel tank assembly because I don't think that's something me or hubby could tackle on our own.

 

[jrSS]

Deleaships will not replace 02 -03 fuel sending units. That's what my letter said when I had my 06 envoy's done. My 2 cents.

 

[Voymom]

Deleaships will not replace 02 -03 fuel sending units. That's what my letter said when I had my 06 envoy's done. My 2 cents.

The dealership here will replace mine, but it's going to cost me about $1800.00 parts and labor. But that's if I need a new sending unit, and not just a level sensor.

 

[jrSS]

Well my bad....they will replace them you'll just pay an arm and leg to do so. ; had the voy done last year and they charged me $115 and that was 1/2 the $$

 

[Voymom]

Well my bad....they will replace them you'll just pay an arm and leg to do so. ; had the voy done last year and they charged me $115 and that was 1/2 the $$

Did you have the leveling sensor replaced or the sending unit?

It would cost us $158.00 from the dealership for the leveling sensor, but I'm sure I could get it cheaper else where. I'm not to sure about the sending unit as I was told I need to replace the entire fuel tank assembly.

The $1800.00 is for the entire fuel tank assembly, for the dealership to do, I didn't ask about the fuel leveling sensor as I'm sure it may be something we can either do our own, or get help doing it. It's $500.00 alone for the damn fuel tank assembly

 

[MAY03LT]

I called the local delearship, told them I needed the Fuel sending sensor, they told me to replace that in this truck I need the entire fuel tank assembly. That costs $500.00...

Dealership personnel incompetency at its finest.

...and there is NOTHING about splitting the cost even though I am under 120k miles.

We're not covered for the sensor.

The mechanic I spoke to, as he was playing the "parts" person due to the parts guy being out for the day, and he told me I only need the little floaty thing, the fuel leveling sensor...that is $158.00 and no splitting costs with that either.

Was that the installed price? The delco sensor goes for $90 at rockauto.

So, I'm a bit confused as I am still quite a noob and trying to learn as much as I can. I'm confused as to exactly what part I need to replace. Is it the fuel sending unit, the fuel level sensor?

Fuel level sensor, fuel sending unit, both refer to the same thing. Floaty thing is also acceptable in my universe.

 

[jrSS]

Pretty sure it was just the sensor. wish I would have kept the reciept. Gave all the records and such to the delearship when I traded the voy in.

 

[rcam81]

Back when I had my 03 TB, either it wouldn't fill completely or it would puke gas when it was almost full. There is a TSB for these issues on the early model 360's. The remedy was a new fuel filler neck and installation by the dealer according to the TSB.

 

[Voymom]

Dealership personnel incompetency at its finest.

I agree. I always call the dealership and price out parts I need to see exactly what I'm saving when I don't buy from them. It makes me feel a million times better, even when the difference is a few dollars.



We're not covered for the sensor.

I figured as much, we're not covered for a lot of stuff that we should be.



Was that the installed price? The delco sensor goes for $90 at rockauto.

Yes, That was installed price


Fuel level sensor, fuel sending unit, both refer to the same thing. Floaty thing is also acceptable in my universe.

Thank goodness! lol Now I don't feel as stupid.

Does the fuel tank need to be dropped in order to replace this part?

Back when I had my 03 TB, either it wouldn't fill completely or it would puke gas when it was almost full. There is a TSB for these issues on the early model 360's. The remedy was a new fuel filler neck and installation by the dealer according to the TSB.

Mine only causes the pump to stop periodically, It's not a huge issue for us, as we know how much it should cost for the amount of gas we need, and just a simple wiggle of the gas pump stops it. It doesn't spit out gas either, not saying that these issues won't eventually happen. Also I checked TSB for recalls, and the only recall I have on my vehicle is the back passenger(drivers side) door.

 

[MAY03LT]

Does the fuel tank need to be dropped in order to replace this part?

Yep, gotta drop the tank and remove the fuel pump module to swap out the floaty thing.

 

[Voymom]

Yep, gotta drop the tank and remove the fuel pump module to swap out the floaty thing.

I thought so, Thank you!!

 

[Sparky]

Does the fuel tank need to be dropped in order to replace this part?



Mine only causes the pump to stop periodically, It's not a huge issue for us, as we know how much it should cost for the amount of gas we need, and just a simple wiggle of the gas pump stops it. It doesn't spit out gas either, not saying that these issues won't eventually happen. Also I checked TSB for recalls, and the only recall I have on my vehicle is the back passenger(drivers side) door.

I know the EXT/XL has a different fuel neck, but my SWB TB would do that. Usually couldn't fill at full pump speed, and sometimes it was so bad that I could barely fill the tank. I found the hose was kinked where it attached to the filler tube near the top, obstructing the flow. Then my neck rusted and leaked all over every time I filled the tank Replaced it with a used one I found on ebay that wasn't kinked and it has been perfect ever since.

Anyway, might be worth looking at the neck just to be sure it doesn't have some kink in it from improper installation. Mine looked like it had been removed at one point and reinstalled improperly (one of the nuts was missing that holds the neck to the quarter panel).

Something to try on the sender unit that might work is put a bottle of the injector cleaner in the tank then fill it up. The good stuff is supposed to help remove varnish and such, maybe you just have a little buildup on the sending unit and some injector cleaner would clean that off? No harm in trying anyway and if nothing else you know your injectors are sparkly clean

 

[Voymom]

I know the EXT/XL has a different fuel neck, but my SWB TB would do that. Usually couldn't fill at full pump speed, and sometimes it was so bad that I could barely fill the tank. I found the hose was kinked where it attached to the filler tube near the top, obstructing the flow. Then my neck rusted and leaked all over every time I filled the tank Replaced it with a used one I found on ebay that wasn't kinked and it has been perfect ever since.

Anyway, might be worth looking at the neck just to be sure it doesn't have some kink in it from improper installation. Mine looked like it had been removed at one point and reinstalled improperly (one of the nuts was missing that holds the neck to the quarter panel).

Something to try on the sender unit that might work is put a bottle of the injector cleaner in the tank then fill it up. The good stuff is supposed to help remove varnish and such, maybe you just have a little buildup on the sending unit and some injector cleaner would clean that off? No harm in trying anyway and if nothing else you know your injectors are sparkly clean

Hmm, I wonder if mine is kinked then? Maybe I should have it checked. As far as adding injector cleaner....we don't have a lot of good luck with putting stuff like that in this truck lmao. If I were to use an injector cleaner, what would you recommend? That way I don't end up using something like engine restore That was a nightmare!! Mat(my hubby) suggested that maybe the sensor or floaty thing is stuck? Not sure if that can happen or not though? I swear this truck hates me lol

 

[ElAviator72]

The sending unit "recall" (where GM meets you halfway on repair costs) is only applicable to '05 and up. GM redesigned the uel system in '05 by deleting the fuel filter, and that was just enough to cause the sending unit to get gunked up prematurely

 

[tokahao]

FWIW, I had this problem back in '07 when filling with anything but 87 octane. I dealt with it until I moved to Germany and the lowest octane they had was 91... of course the problem came back. I tried 4 treatments of Techron to no avail. I eventually broke down and bought the fuel level sensor from Parts.com, here's my e-mailed receipt:

Spoiler

Items Ordered:
Item: Fuel system, Fuel system components, Level sensor, W/long wheel base, W/long wheel base - 2005-07 - 2005-07
Price: $76.62
Tax: $0.00
Qty: 1
Total: $76.62

-----------------------------
Items Total: $76.62
Shipping: $11.49
Handling Fee: $2.00
Order Total: $90.11

Auto Parts - Parts.com, For Every Part of Your Life

Best of luck to you getting this fixed, I ran out of gas in the garage while warming it up one cold winter day.

 

[AbsoluteZero]

Mine only causes the pump to stop periodically, It's not a huge issue for us, as we know how much it should cost for the amount of gas we need, and just a simple wiggle of the gas pump stops it. It doesn't spit out gas either, not saying that these issues won't eventually happen. Also I checked TSB for recalls, and the only recall I have on my vehicle is the back passenger(drivers side) door.

There wasn't a recall, just a TSB was issued if a customer complained. You might check your local library to see if they have a subscription to one of the car repair sites. I found the TSB on ours. The titles reads:
Vehicle is Difficult to Fill with Fuel or Filling Station Pump Shuts Off Before Tank is Full or Fuel Spits Back/Out When Filling Tank (Replace Fuel Tank Filler Upper Pipe and Lower Hose) #04-06-04-003A - (08/11/2004)
The "A" revision was because of a part number(s) update and it did apply to the XL version.
If you can't find the TSB send me a PM and I'll try to download from the library site.

 

[HARDTRAILZ]

PM me if you want to buy just the fuel level sensor...I got one and never bothered to install it.

 

[Voymom]

PM sent! Thanks Hardtrailz.

I will respond to the other posts once I get some coffee in me and wake up a bit.

 

[hotrod1984s10]

I've had the same issues as you Voymom. My fuel gauge now reads empty all the time. The fix is to replace the "floaty" thing. There is a really good step by step picture tutorial on the "other" site if you want to tackle it yourself.

 

[Voymom]

I've had the same issues as you Voymom. My fuel gauge now reads empty all the time. The fix is to replace the "floaty" thing. There is a really good step by step picture tutorial on the "other" site if you want to tackle it yourself.

Thanks Hotrod! I will probably venture over to the "OS" when the time comes to do the job. I will definitely do a write up over here as well, with plenty of pictures as always. Luckily hubby has dropped a tank or two in his lifetime so we won't be staring at each other with our hands wrapped around each others necks lol.

I try to do a lot of the work myself, but he does all the parts of the jobs that require muscle. It's fun to learn together, but there are times where we want to put each other 6 feet in the ground lol

 

[jccrall]

OK this thread sounds like what I have to deal with.

My 2007 Trail Blazer has started doing strange things with the fuel gauge. It will signal empty (low) when I have half a tank and will move 1/4 tank up or down in just a few blocks driving.

Where do I find out about GM splitting the cost for replacing the fuel sensor??

Thanks, John

 

[ElAviator72]

OK this thread sounds like what I have to deal with.

My 2007 Trail Blazer has started doing strange things with the fuel gauge. It will signal empty (low) when I have half a tank and will move 1/4 tank up or down in just a few blocks driving.

Where do I find out about GM splitting the cost for replacing the fuel sensor??

Thanks, John

You should have received a letter from GM about this...I did (even though we're not the original owners of the vehicle). You can probably take it to the dealer, too, who will be aware of the problem. If you need it, there are some members on here who have scanned the original (not sure what happened to mine, but we didnt' get the letter until AFTER we had the sending unit fixed fortunately, it was covered (less a $100 deductible) by our extended warranty).

 

[Jimbo052]

[video=youtube;I25z-7QQJcM]http://www.youtube.com/watch?v=I25z-7QQJcM&feature=youtube_gdata_player[/video]

 

[BRomanJr]

Great video Jimbo, I've done almost a dozen fuel pumps like this and you documented the process perfectly. I liked how you went back and added detailed instruction and pictures to the video for clarification.

One comment,
When I've come across those (2) clips you show on top of the fuel pump module lines and elsewhere, I was able to just press on the large white surface of the clip (top side on your video) to release and then slide the line off, no need to remove the clip.
(although I did it the same way you did a couple times)

Bob.

 

[Jimbo052]

I should probably be clear. I'm not the author of the video, I just found it a while back and thought I should share!

 

[BRomanJr]

I should probably be clear. I'm not the author of the video, I just found it a while back and thought I should share!

Sorry, I did not realize that, thanks for the clarification, I just hope my comments helps someone.

 

[jrSS]

Damn it!!! My fuc$% sending unit acted up on me this morning. Thought I was gonna get lucky on this SS. Already had the voy done wen I had it. Looks like its down hill for the sending unit from here. Damn damn damn!!!!!!

 

[The_Roadie]

A 2007 SS isn't covered by the recall/TSB?

 

[jrSS]

Yea it is. But I don't wanna take it in. I hate going to the dealership. And I don't wanna do it. Screw that. Its my dd. No down time. Its fine now. And the engine light didn't come on and no chime. The orange low fuel light came on...needle went to 3/4. Then slowly went down to a little above 1/4. (Where it was supposed to be). But eventually I will have to take it in.

 

[The_Roadie]

Yea it is. But I don't wanna take it in. I hate going to the dealership. And I don't wanna do it.

If you think that way, they've won. Annoy them by getting the work done at a discount. And ask for a loaner.

If this ever happened to me, and it won't because I'm 2004, I'd seriously consider driving 25 miles to another town where the dealers weren't all drinking from the same brain-destroying Koolaid as they must be around my house.

 

[jrSS]

Lol. Uve got a good point. Never thought of a loaner. I'll look into this.

 

[tom1999d]

I just bought a used 07 SLE and the very next day the fuel level sending unit went whacky, full empty, ces light the whole 9 yards... I put some Gunk eng cleaner and now it is moving. I'll try another then if necessary got 1/2 way with the local dealer on replacement.

 

[tom1999d]

I just bought a used 07 SLE and the very next day the fuel level sending unit went whacky, full empty, ces light the whole 9 yards... I put some Gunk eng cleaner and now it is moving. I'll try another then if necessary got 1/2 way with the local dealer on replacement.

My SES light is out and the gauge reads false high and false low but the Gunk cleaner seems to be helping. I'm going to add another bottle at the next fill up. So far so good...

 

[tom1999d]

Despite several fuel cleaner treatments I ended up biting the bullet and at 103k miles I got it replaced at the dealer. My cost was $136.04. I watched a YouTube video of a guy replacing his. It is a tough job to tackle and I'll tackle almost anything.

 

[Tmn8tr]

I pulled my tank yesterday and replaced my pump assembly, since my fuel gauge had been acting up as well on my 05 EXT LS. I got the new one in and buttoned it up, ran it for 30 minutes in the driveway with no leaks. Took it down to the gas station and filled it up, and my gauge read full for the first time in the 4 months I've owned it. Backed into my (very) steep driveway when I got back home. When I got back in to take off to dump the kids somewhere (approx. 45 min. later) I smelled gas strong, but I figured the kids had messed with the old pump sitting on the garage floor, and we drove away. When I returned a few minutes later, I notice a puddle on the driveway. I crawl back under the truck and look, but can't find any leaks. I drive it some more and notice the fuel gauge is freaking out again, and now I've got a CEL saying that the Air intake temp is out of range.. When I shut it down this time I notice the gas gauge won't drop below 1/4 tank. Ignition off, on, off, on...no change- hyper on, 1/4 tank off. I doubt that my fuel level sender has died this soon, and am wondering about the gauge now, how do I change it? My wife then goes out at 9:30 to retrieve something from the truck and comes in saying the headlights won't shut off. How can all these things be related? Like I said earlier, we have only had this for 4 months and it is nickel-and Dimeing me to death. The stealer I purchased it from won't even talk to me, they say that they sold it to me for "too cheap."
My wife is wondering if we got a lemon.
I am leaving on the 3rd of March and driving out West for a couple of weeks, and I'm not feeling too confident in my trucks abilities.
>T

 

[Tmn8tr]

Well, we went out to go to dinner, and she won't start. No codes, no idiot lights, just regular cranking with no start. I'm so glad it didn't happen when we were out in it this afternoon.
I'm going to have it towed in to the mechanic in the morning, I am tired of messing with this thing.
>T