Fuel sending unit
Thread Starter
Team Owner
Joined: Aug 2007
Posts: 136,140
Likes: 2,432
From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
Fuel sending unit
Anyone ever heard of doing the ol' "disconnect battery for 10 minutes computer cure" fixing an intermittent fuel gauge issue?
(yes, I know about the sulfur build up issue but someone suggested the above first and I've never heard that before)
(yes, I know about the sulfur build up issue but someone suggested the above first and I've never heard that before)
Instructor
Joined: Apr 2007
Posts: 154
Likes: 0
From: South Louisiana/Mississippi
I'll be a monkey's uncle - IT WORKED
I have a 2007 m6 with 109K miles on it and my service fuel system displayed and the guage went to empty. It gave no warning. I then topped it off with fuel and still no cure. I then picked up 2 bottles of the chevron fuel treatment and drove about 60 miles with still no cure. I just got home after stopping by the dealer only to have them tell me that they have never heard of this problem. I read this post and figured I would have to try disconnecting the battery for 10 minutes. IT WORKED. The guage works perfectly and no DIC readings.
Thanks for the tip
Thanks for the tip
Melting Slicks
Joined: Oct 2009
Posts: 2,259
Likes: 1
From: Las Vegas NV
St. Jude Donor '10
I JUST had the fuel gauge issue a few weeks ago.
I had to go out of town for a week just as it was getting more frequent. I poured in a bottle of Techron and drove about 3/4 tank of fresh gas through it before I left.
After I came back, I discovered a dead cell in an 8 month old red top Optima, swapped it out, and the gauge works like normal. :P
In essence, yes...I did disconnect the battery...but it was actually already dead. LOL!
But between letting the Techron soak the terminals for a week with the battery essentially "disconnected", all is well now. I figure I got a bad tank of gas as it happened just a few miles after I filled up.
I had to go out of town for a week just as it was getting more frequent. I poured in a bottle of Techron and drove about 3/4 tank of fresh gas through it before I left.
After I came back, I discovered a dead cell in an 8 month old red top Optima, swapped it out, and the gauge works like normal. :P
In essence, yes...I did disconnect the battery...but it was actually already dead. LOL!
But between letting the Techron soak the terminals for a week with the battery essentially "disconnected", all is well now. I figure I got a bad tank of gas as it happened just a few miles after I filled up.
Instructor
Joined: Apr 2007
Posts: 154
Likes: 0
From: South Louisiana/Mississippi
Thread Starter
Team Owner
Joined: Aug 2007
Posts: 136,140
Likes: 2,432
From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
Well....did the ol' battery disconnect thing and the problem still exists.
So, when I get back from my 10 day road trip in September, into the shop it goes...
So, when I get back from my 10 day road trip in September, into the shop it goes...
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Pro
Joined: Sep 2010
Posts: 535
Likes: 10
From: Fort Worth TX
I got this problem a week or so ago, went out and bought the techron... researched for hours and just now found this thread. I have an 08' with almost 70k miles and haven't tried the techron yet. Unplugged the battery and it works again. Couldn't be happier right now... THANK YOU
Thanks again for the tip.
3rd Gear
Joined: Sep 2011
Posts: 3
Likes: 0
From: Star Valley AZ
3rd Gear
Joined: Sep 2011
Posts: 3
Likes: 0
From: Star Valley AZ
Fingers crossed!
Burning Brakes
Joined: Dec 2004
Posts: 802
Likes: 2
From: North Royalton Ohio
FWIW my '98 C5 @ 24k started having the fuel gauge needle drop to E and trigger the "check gauges" warning. Dealer remedy was to replace both tank units. Problem was so bad many times 5-10 minutes out needle dropped, most times turning ignition off then restarting functioned ok, sometimes failed again same trip repeatedly.
Would buy the Techron when on sale @ 2 for 1 [20 gallon strength] and would add it every second fill up from 24k til sold @ 37k. Took several months and problem became very intermittent, would add two bottles over winter layup. Never had an issue with rubber parts deterioration. Use it in all my vehicles quarterly. Just my .02
Would buy the Techron when on sale @ 2 for 1 [20 gallon strength] and would add it every second fill up from 24k til sold @ 37k. Took several months and problem became very intermittent, would add two bottles over winter layup. Never had an issue with rubber parts deterioration. Use it in all my vehicles quarterly. Just my .02
Le Mans Master
Joined: Dec 2004
Posts: 5,491
Likes: 806
From: West coast CA
And in the case of the fuel gauge, the cause of the problem is well-known and obvious: dirty terminals on the passenger side fuel level sender.
Advanced
Joined: Jan 2010
Posts: 54
Likes: 1
I have had great problems with this issue in the past. Techtron seemed to help some. The complete fix for my 2005 was not using gas with ethanol. After I started using 100%GASOLINE I have never had anymore problems. It has been almost a year now. What was always a problem is completly gone.
Also if you guys were unaware - gas milage and horse power are greater with 100% gasoline. Ethanol has far less energy than 100% gasoline.
My car is a 2005 Z51 MN6 daily driver
Also if you guys were unaware - gas milage and horse power are greater with 100% gasoline. Ethanol has far less energy than 100% gasoline.
My car is a 2005 Z51 MN6 daily driver
Thread Starter
Team Owner
Joined: Aug 2007
Posts: 136,140
Likes: 2,432
From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
Pro
Joined: Sep 2010
Posts: 535
Likes: 10
From: Fort Worth TX
I had the problem again yesterday, after resetting the battery it worked fine for a month or two but I put some more technron in and pulled the battery for a few minutes and it's okay again. Hopefully it won't become more and more frequent or I will have to do something about it. This time it happened though the check engine light came on as well, which didn't happen last time.
Thread Starter
Team Owner
Joined: Aug 2007
Posts: 136,140
Likes: 2,432
From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
I had the problem again yesterday, after resetting the battery it worked fine for a month or two but I put some more technron in and pulled the battery for a few minutes and it's okay again. Hopefully it won't become more and more frequent or I will have to do something about it. This time it happened though the check engine light came on as well, which didn't happen last time.
Interestingly, what I found defective wasn't any sort of sulfur or other contaminant buildup on the wipers and/or potentiometer substrate (in fact, they're all gold plated and they were clean and shiny) but rather micro cracks in the ceramic substrate itself causing intermittent connections.
Le Mans Master
Joined: Dec 2004
Posts: 5,491
Likes: 806
From: West coast CA
The row of contacts that the fuel level sender wiper touches. That's what's getting de-gunked by the Techron. After a while, the ones on the passenger side tank turn visibly grey and dingy. Meanwhile, the identical unit in the driver's side tank remains shiny and nice because it spends most of its life submerged in gasoline.
Thread Starter
Team Owner
Joined: Aug 2007
Posts: 136,140
Likes: 2,432
From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
The row of contacts that the fuel level sender wiper touches. That's what's getting de-gunked by the Techron. After a while, the ones on the passenger side tank turn visibly grey and dingy. Meanwhile, the identical unit in the driver's side tank remains shiny and nice because it spends most of its life submerged in gasoline.
YMMV of course
