whoie15

I have an auto non z51 c7. had it since May.
I filled up my gas today and I know I filled it FULL but for some reason, the gauge reads exactly ZERO (Very bottom). It would not move, I tried turning off the car and turning back on, still nothing. Yes, I am confident, I filled the tank fully, I got my receipt after for proof.
Any of you guys had this problem? Any suggestion? Other then take it to the dealer tomorrow (which im going to do). hopefully its not a serious problem...

conadslv

Ive been dealing with this problem all month...I first noticed my gas gauge not working and the engine light come on earlier this month. I took it to the dealership the next day so they could take a look at it and see if they could fix it. It was at the dealership for a few days bc they had to "drop the gas tank" which was a full days worth of work in and of itself. Once they "fixed" the problem with the gauge...i cant remember how, i think with a simple reset maybe. Anyways, I picked it up and for a few days every thing was working fine until one night i put it in track mode and did some aggressive driving on some empty roads. Thats when the engine light came on and the gas gauge went to zero again. This happened on a saturday and wouldnt be able to take it in until monday. Unfortunately bc of my job i had to leave that sunday and was gone for a week so i left it in my garage. when i came home a week later i was curious to see if the problem might have fixed itself so i attempted to start it up with no luck. For some reason the battery had some how drained and would no longer let me start it, all the lights in the car turned on but would not start...only a constant clicking noise when it was trying to start. Didnt leave the lights on, the FOB wasnt left in the car, nothing i did was out of the normal so why it wouldnt start was a head scratcher. Had a flatbed pick it up that monday (9/22) and take it back to the dealership. It wasnt until Friday (9/26) that they told me that they had ordered a new modulator and it wouldnt be here until the following tues or wed (today). I called today and they said they should have to modulator installed by thursday/fri and hopefully that is what was drawing the battery power which caused it not to start. if it is then they said i shoudl have it by friday afternoon...if not then they have to start troubleshooting and figure out what caused the battery to die which could open up a whole other can of worms. Hope this helps and gives you a little insight as to what you might be dealing with when u take your car to the dealership tomorrow. Best of luck!

I also have an auto, non z51. i ordered it on 1/17 and took delivery of it 2/28.

whoie15

Thank you so much for the reply and this resourceful info. I will take it to the dealer tomorrow and I hope they really don't have to take off the whole gasket. at one point I thought I added diesel in my tank or something. So. I drove back to the gas station and I was right , the pump I used did not have a diesel pump. Hahah I was paranoid, I had to see..

collinsmk

I had a similar issue with my 2005 Z51, they dropped the tank and replaced a faulty switch. No other issues whatsoever (6yrs/35K miles).

I was a little worried getting another first year Z51, but all is good after teo weeks and 600 miles. Hopefully it's an isolated incident...

Let us know what the dealer says.

Good luck!

Mike

bluvette2000

Sulfur deposits on sending unit caused this frequently on C5's. An occasional bottle of techron in the tank always seemed to cure and then prevent it.

whoie15

Hey mike,
Thank you for the heads up, I'll make sure to keep u guys posted. Out of curiosity how long does it take to usually "drop the tank and replace the switch?" Hopefully nomore than a day =T

conadslv

what they told me originally was 8-12hrs to drop the gas tank. not sure how true that is but I would anticipate your car to be in there for at least a couple of days. of course that all depends on how efficient and knowledgable your tech is.

donsar

Same problem with my C6. Tank had to be dropped and a new sending unit installed. Probably caused by sulfur or other deposits that had built up. This can be prevented by use of Top-Tier fuels. If I recall, the cost was over $1500.

AFVETTE

Both of my C6's (2006 Z51 and 2007 Z06) were afflicted with this bug. The Techron seemed to help. Could be the gas you are buying.

Good luck

Tom

Chevy Cust Svc

Hey whoie15,

We're sorry to hear that you're experiencing a concern with your C7! Please let us know how your visit goes, and if our team can look into it further.

Marissa
Chevrolet Customer Care

whoie15

I turned my car into the dealer at 7am. I should get some answers by 2pm. I really hope they don't hold it over the weekend . I kinda enjoy my car, and enjoy it more on the weekend... Will keep u guys posted

HAD2HAV2

Drive the car for around 10 miles. I bet the gauge will start working. I had the same thing happen on my C6 A6 at 50,000 miles. The fuel sending unit (fuel module) had to be replaced. Happened on my extended warranty and saved me around one grand (mostly labor). Man, I was hoping this problem was fixed with a better part during the build. Yes, it will take a couple of days to fix. I got to drive a Volt. Techron did not work for me.

whoie15

Hey Guys,
Its Keith, the creator of this post. First just want to say, I did try driving the car for over 20 miles but still no luck +T thank you for the suggestion "HAD2HAV2".
As for the progress, so this problem happened weds night and I gave the car to the dealer the next day at 7am. Called them at 4 pm to see the status ( i figured it wasnt done ) so i just asked them , "please give me the good news and bad news". Apparently, they had no bad news for me. Because I was overexcited I didnt really hear the service guy told me the real cause of the problem other then " we just need a part (im assuming new sensor?) and we should be good". then he asked me "is it okay for us to keep the car overnight" , of course I said okay.
I know this is not a lot of information, but I will get more today and will post. Im just crossing my fingers they actually have this "part" laying around their facility.

Again, thank you everyone for the insight and help!

KEITH

jerryv

As others have noted, I had a similar problem on my C5 Z06 .. where the gauge would go to zero. At the time, the supposition was that high-sulfur gasoline was affecting the fuel sensor, so I switched to a different gas station and the problem cleared itself up, and never required service. That was about 10 or 11 years ago, and I still have the car and it hasn't happened again since then. Knock on wood. So I have no way to know for sure, but it sure did appear that it was the gas I was using that caused the problem ..

air86

Fill the tank up all the way then drive until the car shuts off, it lets you know when you run out of gas

whoie15

It's scary to know that u have to use certain brand gas to fix this problem. I always fill it up with 91. But I don't think why we should be limited to use shell, chevron, 76, and etc...

whoie15

Picked up my car today bc they said it was ready after 1-1/2 day at the dealer. When I got inside my car, the problem still occurred. I asked them "thought u guys said it was done?" They took the car back, 10 mins I got my car and it was fixed. Guess they did a reset. Anyway, after driving for 15 mins and 5 miles away till getting home, the fuel gauge dropped to 0 again. Nothing changed, nothing was fixed, hard reset won't be the fix. I called them immediately and told them "it's more severe then we think". I will be returning the car back Monday and im sure it won't be 4-5 days till I get it back. this is no fun, oh wells

conadslv

Sounds like you are getting ready to go through exactly what I went through. I just picked up my car today after two weeks at the dealership. They ended up having to replace the fuel modulator. It took longer to order the part than it did to actually replace it. So far no problems but I've only driven it about 20 miles since picking it up. hopefully all is good

whoie15

Hey conadslv,
Out of curiosity did they allow u to take the car home while waiting for the part? Or you chose to leave it there. Also, where was the part coming from? I can't imagine why it would take 2 weeks for a part...I hope everything is good now, let me know if anything changes. I might just have to give the dealer my 2 cents and tell them "fuel modulator. " is the source of the problem

sd7ss

Could someone please enlighten me as to what a "fuel modulator" is, or does in the C7?

Had a similar problem in C5s and C6s where the fuel wouldn't transfer from the right to the left saddle tank because the "fuel transfer pump" wouldn't move the fuel. Got a similar explanation that sulfur in the gas had disabled a fuel level sensor that was part of the transfer pump assembly.

In the case of the C6, this led to a condition where once you used the gas in the left half of the saddle tank; you ran out of gas, with the right tank half still full.

Fix was R&R of the transfer pump/gauge assembly which meant R&R of the right half of the tank. This was both expensive and difficult.