I haven’t done much writing about my C6 Corvette, mainly because it has really been a great car (still is) even with the technology glitches.
However, as you might have gathered from the title there is an issue that I thought I’d jot down along with some possible causes and some preventive measures.
I recently had the problem with my gas gauge flopping round and kicking off the low fuel warning. Interesting enough it only happened immediately after filling up. It is an immediate reaction when I turn the car on. During this most recent incident the gauge remained flat-lined for what seemed a bit longer then it has in the past. I’m talking 20 miles or more with 3 stops full and shut down. It was accompanied by the engine light, which remained on after the gauge went back to normal and the low fuel warning stopped.
The Vette ran perfectly during the event so I’m not too worried , but still you don’t want to have to call the flatbed.
So I dropped a note on my corvette clubs site ACE (Arizona Corvette Enthusiasts) http://www.arizonacorvetteenthusiasts.net and to see what they thought.
Most swear by Chevron gas with its Techron cleaning agent and some were thinking it might be a sending unit and some said it is a common problem with C5 ( the previous generation of Corvettes).
Here are some comments:
—“Use some Seafoam (Autozone, Checker etc.) per directions on the bottle. Techron works also.” My NOTE: Seafoam is tough stuff, you have to be sure to change your fuel filter shortly there after.
—“Same thing would happen to me with Roxxane II (c5). It would show empty when I filled her up. I would use 2 bottles of Techron and then one bottle at every fill up for the next 4 tanks. Problem went away for a while. Then I would use one bottle every 2 tanks and that kept the demon away.”
This one was exteremly helpful……”Well, stop putting gas in it, maybe the problem goes away.”
—“It’s a level sender issue for sure. If Techron doesn’t solve it, you’ll either have to learn to live with it, or replace the faulty sensor. Do you have any way to check the codes to see which sensor is unhappy?” ( I don’t so if it acts up again, I’ll have to take it in.)
—“Two possibilities…. sulphur build up on the sending unit or the sending unit going out. I understand they are a biotch to change.”
—“My C5 had the problem unless I ran Chevron gas in it. About the second tank of non Chevron the gauge would go crazy. I would switch back and the problem went away.”
—“This was a common occurrence on the ‘early’ C5’s. It usually happened when high sulphur content fuel was put in. Some of the fixes were switching gas to adding a bottle of Techron every once in a while. The real ‘fix’ was a reflash at the dealer. Apparently the sender was a bit too sensitive, so they slowed it down.
I had the issue occasionally on my 99, but when I put a 2002 Z06 operating system into the computer, it went away.
Since you have a C6, I would expect that the issue isn’t a reflash. My guess would be that maybe you got some high sulphur content fuel or your sender is acting up in some way, maybe a poor or intermittent connection somewhere along the line.
—“You could try a treatment with Techron and see if that ‘cleans’ it up. ”
—“I was using the Techron trick in my C5. I switched to Gumout Regane Fuel System Cleaner. I t seems to help, although my gauge still jumps to E at times when below 1/3 of a tank. Good luck. It sucks to not really know how much fuel is in your tank. Although a Vette is light in comparison to other cars, I just can’t see myself pushing it into the gas station.”
So there you have a round of discussion on the topic.
Now the fuel leveling sensor is used because the C6 had two tanks and this keeps the tanks level. Which is important especially if you are running auto cross. Here is area a couple of graphics from http://www.corvetteactioncenter.com:
So you can see that it would a chore to replace. So I’m going to try the Techron and hope it works. I’ve been cautioned that I need the Fuel System Cleaner – not the injector cleaner. Here’s a pic:
Get the Fuel System Cleaner.
I’ve used my first 12 oz can and I’m currently at half a tank. I’ll fill it up again in a couple of days (Yes..when you normally drive it like you just stole it you tend to have to fill up – now and again..mostly..again!) and I’ll try to capture the event on my trusty Android.
Stay tuned (up). {someone please say they get that}
Thanks for reading
Tim
I’m currently having this problem also, my C6 had to be flat-bedded to the shop. (ran out of gas but was on my way to store to buy Techron) They called me and told me that if it’s the sending units they could access them through the wheel-wells. I’m waiting for their phone call as I’m typing this.
It’s most likely the the sending units. There are two sending units and end of this story is that they had to replace one and then shorted out the other in the process to both got replaced. They had to drop the exhaust in the process.
So if they call you pin them down on which sending unit if possible.
Thanks for the fix I was driving a log distance and got a bad tank of gas and right after a fill up this occurred. Concerned the hell out of me because I was 600 miles from home.. WTF I will get to a chevron ASAP!! Question did the engine light go off by it’s self or did I need to take it to the dealer? Sorry if I seem slow or uninformed My First Vette..lol
Thanks
Hey Chris. Yes the engine light does come on and will eventually reset. Have fun and keep the shinny side up.
Tim
What’s the update? My 07 C6 started this problem recently too, exactly like your problems. I’m on my 2nd Techron Fuel System Cleaner. Would love the update since you last noted 4 months ago. Thanks in advance.
Here’s what I know so far. Techron Treatment has no effect on the issue. What’s next? I’ll have to remove the gas tanks (it has two) and change the sensors or replace unit. Most of the comments I got back said…”You’ll just have to live with it. But that is not an option.
Thanks for reading.
My 2001 Impala had this same problem, and I went the same route as you with fuel system cleaners such as Techron and Seafoam. None cured the problem. I hate to rant, but this is one of the thousands of reasons of why GM needed a bail out. From mid 1990s Grand Prix to each and evey Impala to your Corvette the fuel sender has been an issue. Rather than correct a known design issue and practice ‘continuous improvement’, GM chooses to continue with known defects and just let owners deal with it down the road.
Disclaimer: my 2001 Impala was the worst car I have ever owned, and I drive a LeBaron daily.
Having said all this, back in the early 1990s when I bought my Plymouth Laser (Mitsubishi Eclipse), a Chrysler Tech who was my neighbor recommended a bottle of Techron at every oil change. This is a practice that I continue to this day. Everytime I buy a oil filter, I get a bottle of Techron. My trusty 1990 LeBaron at 122k miles still has not had a fuel injector service, and has all of the original fuel system componets such as fuel pump, regulator, and all injectors. One Techron treatment evey 3K milles since new. I do change the fuel filter every 12K miles.
BTW, the (original) fuel sender still works well at 20 years old and 122K miles.
Thanks for the place to rant and rave, Bill
Bill..you know I love the LeBaron and I’ve got to say that if it weren’t for you religious, almost cult like adherence to strict maintenance it would have gone the way of most K-Cars. Now let’s take to the drag strip and get some video of it at the tree.
wow tim….very detailed and informative article….bet helpful for the c6 crowd for sure.
i am enjoying your detailed articles.
Thanks Tony. I’ll have some Mustang projects coming up – all new carpeting and I’ll be in stalling a Borg Warner T10 4 speed transmission.
I know it’s not a Corvette but is fun.
That would be annoying. My 92 Tbird leaked fuel at the sender. My temp fix was to not fill the tank. That was inconvenient at best. Last year when I rebuilt the front suspension I also bought a new sender and pump. Not a pleasant task. Although it’s one tank it is basically two. The driveshaft is above and the exhaust is below. Instead of removing the exhaust I unbolted the tank and let it lay on the exhaust and tilted it to the passenger side and had just enough room to change out the pump/sender assy.
I’m not looking forward to having to replace the U joints as the tank has to come out to get the drive shaft off the differential which means the exhaust has to come off too. What were those engineers thinking? I think Ford just couldn’t afford another car that would blow up in a rear end collision so they put the tank inder the rear seat just a couple of niches forward of the diff. With modern cars nothing is simple anymore. The price we pay for both technology, safety and packaging regulated by the government.
On another note I just read that the Chevy Caprice is back for 2012. It’s really the 2010 Pontiac G8 by another name. Now we need the station wagon version….
That’s a lot of work Steve. I’m think Fuel Cell for your Tbird…that trunk is big enough.
I haven’t heard about the Chevy Caprice…hopefully they do something cool with the body..didn’t like the G8 body style too much.,..might as well have been a Hyundai