Fuel gauge problem

Mus

New Member
Dec 13, 2015
5
4
3
37
Miississauga
Car
2007
#1
My fuel gauge keeps going up and down. For example I will fuel up it would be ok full and then I drive for a while goes down says need fuel and the back up after a while. Any ideas what it can be?
 

ddgermann

High RPM Poster
Jul 1, 2017
1,571
2,076
113
Edmonton
Car
2017 3LZ Z06 Z07
#2
My car does that too. How quickly depends on how many times I push the right pedal more than 1/2 way in a day.

Joking aside.... When you say "drive for a while" I assume you mean a short while. So if you fill up again the tank is almost full?

You have 2 tanks I believe and maybe there is something wrong because of that. Crossover piping or something relating to the level sensor. Should be easy to check with a meter and a "google" service manual. If its a problem someone else has had it is on a forum. Hopefully someone here has the quick answer for you though.
 

Mus

New Member
Dec 13, 2015
5
4
3
37
Miississauga
Car
2007
#3
Yes I mean a short while and some days I think the problem is gone cuz I will drive a day with no issue but then the next day it will happen again the gauge will go all the way to empty.
 

ddgermann

High RPM Poster
Jul 1, 2017
1,571
2,076
113
Edmonton
Car
2017 3LZ Z06 Z07
#4
Yes I mean a short while and some days I think the problem is gone cuz I will drive a day with no issue but then the next day it will happen again the gauge will go all the way to empty.
Wonder if you have ground issues?.... Seems intermittent which doesn't sound like a sending unit failure.
 

Black 03 Z06

High RPM Poster
Oct 30, 2013
4,993
3,367
113
Haliburton, Ontario
Car
2003 Z06
#5
Could be right off base here but it seems to me that I read somewhere that the "float" gets gummed up with crap gasoline and causes all sorts of issues. Again, could be wrong but I think that is why some folks were using Techron in they fuel system. Don't think you can buy in Canada however.

Have to admit Derek's response is probably more accurate.

Good luck getting it sorted.
 

Paul C&

Active Member
Dec 21, 2017
249
262
63
Vancouver, BC
Car
2017 G.S. Z07 pckge
#6
Humm, interesting. As per Black 03 Z06 and ddgermann, ground and float both came to mind. Being that you have a 2007 your float(s) should not be gummed up so I would sway toward a ground or electrical sending unit issue.... hope you can sort it out without to much fuss.
 

SlyMart

Active Member
May 24, 2015
163
44
28
45
Car
1978 Corvette
#7
My 2012 Tahoe does that as well. I need to replace the fuel pump + Fuel Sender altogether since it's all in one module.. Cost is $1300 for the repair + parts. In the beginning, the fuel gauge started to be not accurate. I filled the tank up and the fuel gauge read full and it moved 2 inches and then it never worked again. For a while, it's stuck on empty and sometimes it will let me know I am low on fuel. Sometimes I would hit a bump on the road and the fuel gauge would bump to full and then switch back to empty. I have an engine light on too as well..
 
Last edited:

mbp

Member
Jun 22, 2016
11
4
3
oakville,ontario
Car
corvette 1969
#8
My fuel gauge keeps going up and down. For example I will fuel up it would be ok full and then I drive for a while goes down says need fuel and the back up after a while. Any ideas what it can be?
Hi. I know that some time ago Shell gas was coating / gumming up floats in gas tank and causing problems in GM vehicles. That was a few years back but if yours is a 2007 it may of gotten some of that gas back then and along with a bit of age may be showing effects. Try the dealer, they are aware of the past problem and I believe had a cleaner for the tank that they suggested. Never know might work, inexpensive and easy to try. Good luck.
 

Riley P

Moderator
Staff member
Jan 11, 2009
10,430
1,064
113
Saska-ba-toon!
Car
2000 Z51
#9
My 2000 does (or did) that, once I hit 1/3 of a tank, the needle would drop off the face of the earth. With about 1/8 of a tank left, it would come back to let me know I'm about to run out of fuel. One explanation was a gummed up rheostat, where the sensor would hit a dead zone. I used a couple of bottles of Sea Foam over a couple of tanks and the problem has mostly been gone. Others state that the sulfur in the fuel corrodes the sending unit so it can't be restored, so maybe I am lucky with there being a bit of a film. In my old workplace we cleaned our circuit boards by soaking them in toluene, which is also an octane boost! We had 5 gallon pails of the stuff, but I moved to another job before I could test it out, however, I bet that would clean any film off the sensors. And, if you were to do this option, do some research first to make sure you're comfortable with it.
 

Keith Tedford

High RPM Poster
Apr 30, 2012
3,465
341
83
Ontario
Car
2005 C6 1SB
#10
Hi. I know that some time ago Shell gas was coating / gumming up floats in gas tank and causing problems in GM vehicles. That was a few years back but if yours is a 2007 it may of gotten some of that gas back then and along with a bit of age may be showing effects. Try the dealer, they are aware of the past problem and I believe had a cleaner for the tank that they suggested. Never know might work, inexpensive and easy to try. Good luck.
I use nothing but Shell premium which is supposed to have no ethanol. I've heard of other brands causing problems but who knows. Zero problems with Shell gas so far, with over 80K km on the odometer, knock on wood and the car is a 2005. The electronics on these cars are my biggest worry and can be expensive to repair, as mentioned above.
 

Mus

New Member
Dec 13, 2015
5
4
3
37
Miississauga
Car
2007
#11
I use nothing but Shell premium which is supposed to have no ethanol. I've heard of other brands causing problems but who knows. Zero problems with Shell gas so far, with over 80K km on the odometer, knock on wood and the car is a 2005. The electronics on these cars are my biggest worry and can be expensive to repair, as mentioned above.
Hi. I know that some time ago Shell gas was coating / gumming up floats in gas tank and causing problems in GM vehicles. That was a few years back but if yours is a 2007 it may of gotten some of that gas back then and along with a bit of age may be showing effects. Try the dealer, they are aware of the past problem and I believe had a cleaner for the tank that they suggested. Never know might work, inexpensive and easy to try. Good luck.
Thank you I will try it out.
 

Mus

New Member
Dec 13, 2015
5
4
3
37
Miississauga
Car
2007
#12
My 2000 does (or did) that, once I hit 1/3 of a tank, the needle would drop off the face of the earth. With about 1/8 of a tank left, it would come back to let me know I'm about to run out of fuel. One explanation was a gummed up rheostat, where the sensor would hit a dead zone. I used a couple of bottles of Sea Foam over a couple of tanks and the problem has mostly been gone. Others state that the sulfur in the fuel corrodes the sending unit so it can't be restored, so maybe I am lucky with there being a bit of a film. In my old workplace we cleaned our circuit boards by soaking them in toluene, which is also an octane boost! We had 5 gallon pails of the stuff, but I moved to another job before I could test it out, however, I bet that would clean any film off the sensors. And, if you were to do this option, do some research first to make sure you're comfortable with it.
Thank you Riley I appreciate your reply I will try sea foam see what happens.