# Fixing a gas guage **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [March 24, 2017, 6:02pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099 "2017-03-24T18:02:19Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![dn4192](https://avatars.discourse-cdn.com/v4/letter/d/c37758/32.png) [@dn4192](https://community.cartalk.com/u/dn4192)\ **Post date:** [March 24, 2017, 6:02pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/1 "2017-03-24T18:02:19Z")
I have a 2003 Impala at a little over 129000 and the gas guage on it basically has stopped working. When I start the car it shoots to the F line and doesn’t leave that spot until I turn the car off and then it drops to the bottom. What all is involved in fixing this type of issue? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [March 24, 2017, 6:13pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/2 "2017-03-24T18:13:36Z")
The float in the tank might be stuck. Crawl under the rear of the vehicle with a rubber mallet, and give the gas tank a couple of good whacks to see if that gets the gauge working again. Tester ---
**Author:** ![RandomTroll](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/randomtroll/32/12184_2.png) [@RandomTroll](https://community.cartalk.com/u/RandomTroll)\ **Post date:** [March 24, 2017, 6:22pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/3 "2017-03-24T18:22:41Z")
FWIW, my gas gauge reads low (never quite makes ‘F’, has about a half-tank when it first hits ‘E’, then slowly goes a little bit lower). I keep track of mileage since last fill-up just to make sure I don’t get careless (I usually fill when it reaches ‘E’) but I’ve cut it close and observed that the warning icon doesn’t light until it really is on its last 3 gallons, which tells me that the sender gauge is correct, that I need replace only the receiver gauge, an easier task. ---
**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\ **Post date:** [March 24, 2017, 6:44pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/4 "2017-03-24T18:44:37Z")
**@Bertrand,** You’ve come to the right place! I’ve done this. Got time for a little story? **Usually** ,what happens on these is that a part of the sender (in the tank) goes bad. The sender is attached to the fuel pump module. It is a part called a “wiper” that has tiny “fingers” of metal that disintegrate and the sender becomes intermittent and inoperative. The wiper is on the float arm and “wipes” across a little grid (potentiometer ?) on the sender. That part is usually just fine. The good news is that there’s an access plate in the car’s trunk floor (right side in front of spare tire well) that lets you withdraw the module and replace/repair the sender. Here’s an example of the entire sending unit replacement. [http://www.partsgeek.com/catalog/2003/chevrolet/impala/fuel\_delivery/fuel\_level\_sending\_unit.html](http://www.partsgeek.com/catalog/2003/chevrolet/impala/fuel_delivery/fuel_level_sending_unit.html) Here’s some DIY videos… I’m not sure if these are for 03 Impalas. Take a look. _ **CSA** _ ---
**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\ **Post date:** [March 24, 2017, 7:20pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/5 "2017-03-24T19:20:52Z")
**@Bertrand,** Did the gauge become erratic for a while or did it suddenly just quit (as you’ve described)? _ **CSA** _ ---
**Author:** ![dn4192](https://avatars.discourse-cdn.com/v4/letter/d/c37758/32.png) [@dn4192](https://community.cartalk.com/u/dn4192)\ **Post date:** [March 24, 2017, 7:37pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/6 "2017-03-24T19:37:39Z")
Gauge just stopped working and stays at full. ---
**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\ **Post date:** [March 24, 2017, 8:21pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/7 "2017-03-24T20:21:03Z")
Usually when the sender wiper starts disintegrating the gauge goes through an erratic period before it quits altogether. You’ve got me wondering. _ **CSA** _ ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [March 24, 2017, 8:24pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/8 "2017-03-24T20:24:53Z")
This is the last discussion about the erratic behavior of the fuel gauge level unit (Bert has 3 screen names); > [@2003 Impala Gas Gauge](https://community.cartalk.com/t/2003-impala-gas-gauge/95678): > > I have a 2003 Impala with about 122,000 miles on it. On my recent fill up I by accident put in mid grade over the normal unleaded, now I now that won’t cause any engine issues that I am aware of, but after doing this fill up my gas gauge is not working properly. When I start the car in the morning the gauge will go to where it should given the milage I have driven to this point but as I drive the car the gauge goes up to almost full then down some but never back to where it should be. what mi… ---
**Author:** ![pete\_peters](https://avatars.discourse-cdn.com/v4/letter/p/46a35a/32.png) [@pete\_peters](https://community.cartalk.com/u/pete_peters)\ **Post date:** [March 24, 2017, 8:31pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/9 "2017-03-24T20:31:07Z")
To determine if it is indeed the sender, remove the panel CSA clued you to. Backprobe the purple wire at fuel pump/sender module. Ground purple wire, if gauge goes to empty you know the sender is bad. The whole fuel module will need to be replaced if that’s the case. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [March 24, 2017, 8:45pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/10 "2017-03-24T20:45:24Z")
This OP has stated in many of his other threads that putting fuel in vehicle is the limit of his mechanical skills. He is going to have brake work done so he should just have them look at the gauge problem at the same time and see if he wants to spend the money. The other solution is to check fuel mileage every time he fills up to determine how many miles he can go and not get below 1/4 tank and fill up before that. ---
**Author:** ![dn4192](https://avatars.discourse-cdn.com/v4/letter/d/c37758/32.png) [@dn4192](https://community.cartalk.com/u/dn4192)\ **Post date:** [March 24, 2017, 8:47pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/11 "2017-03-24T20:47:20Z")
Basically what I am doing now is everytime I fill up I reset the milage guage and when I get to around 150-170 miles I refill up as that takes it usually a little past half empty. It’s no real issue but am thking of having it looked at when the do the brakes next Friday. ---
**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\ **Post date:** [March 24, 2017, 9:14pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/12 "2017-03-24T21:14:33Z")
@pete_peters You have given excellent information for testing the sender. I did not know how to do that. > [@pete\_peters](#): > > The whole fuel module will need to be replaced if that’s the case. This I don’t agree with, replacing the whole fuel module. I saw advice like that when I had problems with my sender several years, ago. I provided a link, above, for a new sender. My Bonneville is a similar set-up. I actually removed the sender from the pump module and replaced only the wiper on the sender (fuel level sensor), and reinstalled the sender and then the module. The whole job was about a 2 beer (well, maybe 3) project and it didn’t require assistance for anything. It’s been working for years, now. _ **CSA** _ ---
**Author:** ![pete\_peters](https://avatars.discourse-cdn.com/v4/letter/p/46a35a/32.png) [@pete\_peters](https://community.cartalk.com/u/pete_peters)\ **Post date:** [March 25, 2017, 4:32pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/13 "2017-03-25T16:32:21Z")
That’s good to know about getting sender separately. Here I am, been at this for better than 35 years, work at the same shop for 20, and assume my parts folks know what they’re talking about. LOL! I guess we know about "assume’. Part of their mentality behind replacing the entire module, I believe, is that we’ll see the car for this complaint at 120,000 miles and at 121,000 the pump goes South, and the shop’s left holding the bag since we were “just there”. ---
**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\ **Post date:** [March 25, 2017, 5:00pm UTC](https://community.cartalk.com/t/fixing-a-gas-guage/102099/14 "2017-03-25T17:00:16Z")
> [@pete\_peters](#): > > Part of their mentality behind replacing the entire module, I believe, is that we’ll see the car for this complaint at 120,000 miles and at 121,000 the pump goes South, and the shop’s left holding the bag since we were “just there”. That hasn’t been happened to my pumps, but I hear what you’re saying from a shop standpoint. Get this. When I fixed my Bonneville fuel level sensor (same deal with trunk access), following an online blurb, I ordered a kit (GM# 15824379) from a GM dealer that was stocked everywhere for warranty repair of senders on trucks/SUVs and had a really low price (that happens when GM is paying through warranty). I popped out the module, unclipped the sender assembly, popped off the push-on brass piece the holds the “wiper” and installed only the wiper from the new GM sender kit. Voila! It’s been working for years! It was an inexpensive cake-walk for a DIY’er. I’m not sure, but I think it would work on many models/model-years. _ **CSA** _