And top tier gas. 
C7 Fuel level sensor
Thread Starter
1st Gear
Joined: May 2024
Posts: 1
Likes: 0
C7 Fuel level sensor
My 2017 Grandsport had to sit for about a month due to massive and long flooding near my house and I went to drive it today since I could finally get it out.
Well, now the engine light is on and it says the fuel level sensor is bad and my gas gauge reads inaccurate and is stuck on E even with a full tank(obviously)
I’d consider myself mechanically inclined but I can’t see how or what to do to fix it. I’ve put a bottle of some Techron in the tank and will after driving it for some time again. But my main question is if the fuel system cleaner doesn’t do the job is it difficult to change out the sensor on the c7? And if so what do I do?
Well, now the engine light is on and it says the fuel level sensor is bad and my gas gauge reads inaccurate and is stuck on E even with a full tank(obviously)
I’d consider myself mechanically inclined but I can’t see how or what to do to fix it. I’ve put a bottle of some Techron in the tank and will after driving it for some time again. But my main question is if the fuel system cleaner doesn’t do the job is it difficult to change out the sensor on the c7? And if so what do I do?
Team Owner
Joined: Apr 2013
Posts: 26,227
Likes: 4,355
From: Chirper Island
Yes, it is extremely difficult and expensive to do.
You have to remove the rear end to get to the fuel tanks to replace the sensor.
When I went through this on my '14, the quote was ~$3000 in 2018. I said screw it! I just started setting the trip odo when filling. I then found out the Onstar app would continue to show accurately what my fuel level was, even if I refilled and the dash gauge never changed, so I don't know where it was getting it's info, but it was always spot-on.
You have to remove the rear end to get to the fuel tanks to replace the sensor.
When I went through this on my '14, the quote was ~$3000 in 2018. I said screw it! I just started setting the trip odo when filling. I then found out the Onstar app would continue to show accurately what my fuel level was, even if I refilled and the dash gauge never changed, so I don't know where it was getting it's info, but it was always spot-on.
Team Owner
Joined: Sep 2010
Posts: 32,042
Likes: 4,610
My 2017 Grandsport had to sit for about a month due to massive and long flooding near my house and I went to drive it today since I could finally get it out.
Well, now the engine light is on and it says the fuel level sensor is bad and my gas gauge reads inaccurate and is stuck on E even with a full tank(obviously)
I’d consider myself mechanically inclined but I can’t see how or what to do to fix it. I’ve put a bottle of some Techron in the tank and will after driving it for some time again. But my main question is if the fuel system cleaner doesn’t do the job is it difficult to change out the sensor on the c7? And if so what do I do?
Well, now the engine light is on and it says the fuel level sensor is bad and my gas gauge reads inaccurate and is stuck on E even with a full tank(obviously)
I’d consider myself mechanically inclined but I can’t see how or what to do to fix it. I’ve put a bottle of some Techron in the tank and will after driving it for some time again. But my main question is if the fuel system cleaner doesn’t do the job is it difficult to change out the sensor on the c7? And if so what do I do?
Roadster Madness. 😠
Joined: Sep 2009
Posts: 6,289
Likes: 2,357
From: Ventura Co Ca
SoCal Regional Events Coordinator
St. Jude Donor '13, '20-'21
Before I did anything else, I would suspect the battery. With all the electronics on a C7, a month is a long period if you did not have a battery tender on it. If it is the original battery, that is another possible problem.
I would disconnect the battery (if it is a 2017 replace it), and put a charger/tender on it before I got into the expensive stuff. Just a thought.
I would disconnect the battery (if it is a 2017 replace it), and put a charger/tender on it before I got into the expensive stuff. Just a thought.
CF Community Team
Joined: Apr 2016
Posts: 14,110
Likes: 7,402
From: Pittsburgh
2025 C6 of the Year Finalist - Unmodified
2024 C6 of the Year Finalist - Unmodified
2023 C6 of the Year Finalist - Unmodified
2022 C6 of the Year Finalist - Unmodified
2021 C6 of the Year Finalist - Unmodified
That is an expensive repair, the whole rear drive line needs to be removed to be able to drop the tank(s). Some people have had good luck using Techron, hopefully that will work for you
Burning Brakes
Joined: Nov 2016
Posts: 1,189
Likes: 437
From: San Dimas CA
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Administrator
Joined: Mar 2001
Posts: 368,080
Likes: 24,732
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Try the battery first and see what happens. I certainly would not advocate making stuff up - especially if it may happen to be something that can be covered by a warranty. Hopefully the Techron will show improvement, but it would be good if you posted the DTCs.
Pro
Joined: Jun 2007
Posts: 647
Likes: 135
From: Big Canoe Georgia
I'd go through several cycles of adding Techron if the battery proves to be OK. If you car sat with more than 1/2 tank total (some gas in both tanks) then it is less likely to be a fuel sensor issue. I had the problem with my C6, expensive fix. For now keep more than 1/2 tank of gas in the car. Also when I had that issue with my C6 I did not get a feal sensor message, it was something else is anything (I can't recall).
Drifting
Joined: Jul 2006
Posts: 1,490
Likes: 254
From: Lake Tapps WA.
Team Owner
Joined: Sep 2010
Posts: 32,042
Likes: 4,610
That is an expensive repair, the whole rear drive line needs to be removed to be able to drop the tank(s). Some people have had good luck using Techron, hopefully that will work for you
Race Director
Joined: Dec 1999
Posts: 10,230
Likes: 885
From: Alexandria, Virginia, USA VA
huge rip off with a screwdriver you can fix it
first take off MAF and clean it and reset code see if it comesback.
If MAF is bad I have a known good one for $100
PM me if interested
don't go back
first take off MAF and clean it and reset code see if it comesback.
If MAF is bad I have a known good one for $100
PM me if interested
don't go back
Instructor
Joined: Sep 2024
Posts: 117
Likes: 48
I just bought my 2014 last weekend, and noticed a strong fuel smell. I just thought it was because it hasn’t been driven in a while….is this a real thing I should look into?
Drifting
Joined: Jun 2021
Posts: 1,403
Likes: 943
Yes. Mine was fixed after I noticed a fuel smell coming from the garage after I parked it. The fuel pump hat cracks. That causes it. The fuel level sensor in internal of the pump. So the entire thing gets replaced. Make sure your corvette tech at your dealer is qualified.
Team Owner
Joined: Sep 2000
Posts: 25,007
Likes: 2,706
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Team Owner
Joined: Apr 2013
Posts: 26,227
Likes: 4,355
From: Chirper Island
It costs these companies to get the top tier approval and permission to show it on their pumps and website.
I think Sunoco falls in this camp. They always had high levels of detergent, but have never been licensed as top tier.