Fuel gauge Bouncing F to E

[Tahoewhat]

Just got a 05 Tahoe LT 2wd 5.3 w/ 57k miles for a daily. Always wanted one and finally got a really good deal on it. But my question is, i know there are some known problems w/ them and one i have i believe. My fuel gauge jumps all around, from full to empty to half and in no order. Sit at a red light and fuel gauge will go right to empty, like i just poured out the gas, then jump right back to full. And i will still be waiting at the light. No down hill or nothing like that, sitting completly flat, not moving. I was told it was the fuel sending unit. B/c as far a the pump i hear it and have no problems w/ it starting or driving. Just never know how much gas is in it. Im assuming this is what it is, b/c ive had other cars that did this, but not this bad. just a little off is all they were..

Reading through some of the threads, it looks like a common problem.. So my question is, is this true (fuel probl) and is it better to get a gm one instead of a say Napa, or autozone.. I dont really trust parts store for my fuel pump. But gm wants $400. My price is a little cheaper, but geez they are proud of these things. Also, does anyone know if you can buy just the sending unit or do you have to buy the complete fuel pump assy? (knowing gm im sure i have to buy the whole thing)

Also, is there anything else i should start saving for that might go wrong w/ my tahoe? Figure id get ready for it..

thanks for your time

Mike

 

[Effeckt]

As far as I have seen it could be either JUST the sending unit or the entire pump based on digging through the threads. I have even seen people claim they got new gauges and the issue was resolved. I have the same exact issue as you've just described to make you feel a little better. It is annoying and I plan to get it fixed at some point but have yet to do so but have just been dealing with it as I don't know exactly what to replace and don't want to either try purchasing different items in an attempt to fix it myself or pay someone to figure out exactly what is causing the issue. I'd be really curious to know what resolves the issue point us in the right direction. Hopefully someone can point you in the right place so you don't have to deal with it much longer. If you find out what is causing your issue let me know. I'll take as much info on the problem as possible.

 

[Tahoewhat]

As far as I have seen it could be either JUST the sending unit or the entire pump based on digging through the threads. I have even seen people claim they got new gauges and the issue was resolved. I have the same exact issue as you've just described to make you feel a little better. It is annoying and I plan to get it fixed at some point but have yet to do so but have just been dealing with it as I don't know exactly what to replace and don't want to either try purchasing different items in an attempt to fix it myself or pay someone to figure out exactly what is causing the issue. I'd be really curious to know what resolves the issue point us in the right direction. Hopefully someone can point you in the right place so you don't have to deal with it much longer. If you find out what is causing your issue let me know. I'll take as much info on the problem as possible.

Yeah that is what i have kinda gathered through threads, pump or sending unit. Like you i dont really want to just start replacing things if not needed. Did that before and it was just the gauge it self needed resetting. Could of save me alot of money..
Well at least im not alone in guess how much fuel is left.. LOL... It does get annoying. Kinda funny though, b/c my parents drive it sometimes when im there and they fill it up for me thinking its empty.. lol.. gotta love that..
I will surely let you know what i do and see what fixes the problem. Im thinking i may just try to replace the whole assy. and see what that does. At least then i will know i have a new fuel pump and sending unit. Better peice of mind for me..Since i bought it used..

Mike

just wanted to say also, this forum is awesome. It is not at all like others i have been on. Folks on here are much nicer and very willing to help to the best they can... Just thought id let everyone know that.. and i greatly appreciate it..

 

[Effeckt]

Yeah that is what i have kinda gathered through threads, pump or sending unit. Like you i dont really want to just start replacing things if not needed. Did that before and it was just the gauge it self needed resetting. Could of save me alot of money..
Well at least im not alone in guess how much fuel is left.. LOL... It does get annoying. Kinda funny though, b/c my parents drive it sometimes when im there and they fill it up for me thinking its empty.. lol.. gotta love that..
I will surely let you know what i do and see what fixes the problem. Im thinking i may just try to replace the whole assy. and see what that does. At least then i will know i have a new fuel pump and sending unit. Better peice of mind for me..Since i bought it used..

Mike

just wanted to say also, this forum is awesome. It is not at all like others i have been on. Folks on here are much nicer and very willing to help to the best they can... Just thought id let everyone know that.. and i greatly appreciate it..

Sounds like a plan! I hope you figure it out. Mine isn't horrible yet which is why I still put up with it. After I fill it up it will be all over the place for about 30 miles or so and then it will register for the most part while driving but go on the fritz again when sitting at a light like you were experiencing. I hope your first guess is successful!

As far as the forums are concerned you'll find a lot of the people on here feel similarly which is fantastic as it helps to further that kind of helpful and friendly atmosphere here which is far different than the majority of other forums I've been on in the past. Glad you found us here and are enjoying it!

 

[ravingmadman]

Hi Mike. Yeah, don't spend $400 on a fuel pump, unless they're going to get in your truck and out the door for that cost. I did mine a couple months back, and wrote a how-to on everything you should need to know about replacing your fuel pump (for a 4-door, at least). It is hard to tell if it is your guage that has gone, or the sending unit. I guess you'd need to hook up a multimeter to the lead behind the dash if you really wanted to hunt it down. If you get behind your dash, I might also suggest it's a good time to swap out your bulbs for some cool blue ones, or whatever tickles your fancy. Welcome to the site.

 

[Tahoewhat]

Sounds like a plan! I hope you figure it out. Mine isn't horrible yet which is why I still put up with it. After I fill it up it will be all over the place for about 30 miles or so and then it will register for the most part while driving but go on the fritz again when sitting at a light like you were experiencing. I hope your first guess is successful!

As far as the forums are concerned you'll find a lot of the people on here feel similarly which is fantastic as it helps to further that kind of helpful and friendly atmosphere here which is far different than the majority of other forums I've been on in the past. Glad you found us here and are enjoying it!

Yeah mine doesnt ever register. Except when i fill up all the way, then down hill from there. So i guess mine is worse than yours. LOL.

Yes im glad i found this forum. Its great. So much info and things i want to do to my tahoe that i didnt even know you can. I already did the lights by your feet, since gm didnt do those on the 05. great info all over the place...

Hi Mike. Yeah, don't spend $400 on a fuel pump, unless they're going to get in your truck and out the door for that cost. I did mine a couple months back, and wrote a how-to on everything you should need to know about replacing your fuel pump (for a 4-door, at least). It is hard to tell if it is your guage that has gone, or the sending unit. I guess you'd need to hook up a multimeter to the lead behind the dash if you really wanted to hunt it down. If you get behind your dash, I might also suggest it's a good time to swap out your bulbs for some cool blue ones, or whatever tickles your fancy. Welcome to the site.

Well im i have a good friend that is a mechanic and probly wont charge me much more to put the pump in. With me supplying it though. Do the gauges on these go out that bad. Id hate to spend that and it just be the gauge..
And about behind the dash, i would love to change the bulbs, but from what ive gathered on here, the 05 are soldered in and not like the older ones where you can change easily... Would love to though...

thanks for you guys info...

 

["350Vortec"]

If you turn your key to the acc position. Does your fuel pump whine for a few seconds. Then shut off? And you never hear it again when driving? Or is there a distinct whine coming from the rear end. If there is chances are your pump is going bad, and your sending unit is most likely on its way to. When i had my pump done, the shop found that someone tried patching lines to my sending unit and they rusted off when removed. So i needed a new fuel sending unit to.

Its not worth it to have the pump done, then have the sending unit go shortly after. Just do it in one whack and be happy its done. Plus, almost 100% if your gas guage jumps like that its the sending unit. My buddys tahoe did this for 3 months straight and he finally replaced the Send unit and it was fine afterward.

As for replacement pumps, Ac Delco, Or Delphi make long lasting ones. I wouldnt choose anything but those two. I had my pump,Sending unit, and fuel filter installed for $420.

Remember most auto stores will only guarentee there pumps if you install a new fuel filter at the time of the repair. The first pump the shop put in my truck was faulty, so he charged NAPA the time and replaced it for free.

 

[99Tahoe]

try techron first before you do anything else.

 

[Tahoewhat]

If you turn your key to the acc position. Does your fuel pump whine for a few seconds. Then shut off? And you never hear it again when driving? Or is there a distinct whine coming from the rear end. If there is chances are your pump is going bad, and your sending unit is most likely on its way to. When i had my pump done, the shop found that someone tried patching lines to my sending unit and they rusted off when removed. So i needed a new fuel sending unit to.

Its not worth it to have the pump done, then have the sending unit go shortly after. Just do it in one whack and be happy its done. Plus, almost 100% if your gas guage jumps like that its the sending unit. My buddys tahoe did this for 3 months straight and he finally replaced the Send unit and it was fine afterward.

As for replacement pumps, Ac Delco, Or Delphi make long lasting ones. I wouldnt choose anything but those two. I had my pump,Sending unit, and fuel filter installed for $420.

Remember most auto stores will only guarentee there pumps if you install a new fuel filter at the time of the repair. The first pump the shop put in my truck was faulty, so he charged NAPA the time and replaced it for free.

I will have to check the whine, but i do know that there is no whine when driving or from the rear. I know the whine your talking about, but honestly just havent listened yet. Yeah if i do replace it, then i will be doing both at the same time. Like you stated either or might be on its way also, so i dont want to have to do it all over again. Do it once and at least i know they are both good to go.. $420 isnt bad for all that. Is that with you supplying the parts or w/ parts? If so thats a really good price.

For the replacement, that is what i was thinking ac, or Delphi. Just wasnt sure exactly. didnt think about the fuel filter, i will probly replace that at the same time also. thanks for the reminder. lol. Thanks for your info..

try techron first before you do anything else.

Try techron? techron what? How would that fix my fuel gauge going crazy? Sorry just not sure what that is..

 

[Tahoewhat]

Problem fixed

Alright, for all you guys wanting to know what was the result. Well i bought a new gm fuel pump complete, and just finally got the money and time to install it. Not myself, but my mechanic. All problems fixed. No more bouncing around, no more check engine light on and off. Works like a charm now.. Now i can finally drive around instead of stopping at the gas station everytime i go somewhere just to make it has enough gas..

Just thought i would update, b/c i knew a few wanted me to chime in and let you know how it went..