Ran out of gas for the third time tonight. Been fighting the common 2002 gas gauge problem for 2 years. Gauge goes to empty about every second or third fill up. I have added several bottles of Sea Foam, Techron, and GM Gas Treatment, none of which has worked. And when it does work I do not trust it. I once ran out of gas when the gauge showed 3/8 of a tank left.

Last summer the dealer quoted me $500 each for the two sensors and $1,100 labor to replace them. Said they had to remove the gas tanks to install new sensors.

Is there anything else I can do? Wasn't a TSB issued from GM that reflashes the computer is increase the sensor cutoff tolerances which turns off the gas gauge? Tried a search and did not find it.

My only other thought is to purchase the sensors online from Gene and find a local job shop to replace them for a lower labor charge.

Tonight when I filled up the tanks took 14 gals. I thought this car had a 16 gallon tank.

Any ideas would be appreciated. And do you have to remove the tanks to change the sensors? This car has been flawless except for this.

 

That sucks. Not only running out of gas, but not having a reliable gage. I can't help you with the mechanical part, but I can offer a mathmatical workaround.

1. Fill you tank (which you've done)
2. Push your trip odometer and reset it to zero.
3. Figure 20 mpg (to be on the safe side)
4. Multiply that by your tank capacity (look it up to be sure)
5. If the tank holds 16 gallons, when your trip meter gets to 320, you're going to sucking fumes.
6. Add gas when it gets to 280 or so, just to be conservative.

That's the best I can do.

Sorry I'm not a mechanic.

Michael in KC

 

Yep... I have been fighting the gas gauge issue also. I have already been through the Seafoam and Techron thing. I have also cleaned the grounds in the passenger compartment behind the seats... still no luck. I have not ran out of gas yet, but the gauge has been very erratic.

I read that TSB too about the reflashing the PCM. I am going to try that next week. If it still doesn't work, the sensors are next.

aaarrrrgggghhhh!!!!!

 

What is Seafoam and Techron? Are those products that should be used as a preventive measure?

Thanks.

Michael in KC

 

Techron and Seafoam has helped some cars with this problem, not mine.

I do set the trip odometer and get gas at 220 miles. I filled up last fall and must have driven it some last fall because tonight the trip odometer said 128 miles. The battery did die over the winter and I must have reset it to zero last week when I took the car out for the first time. I was surprised when it ran out tonight with 128 miles showing. Not sure how that happened.

Even at around town mileage of 18mpg, 13 gallons gives 234 miles.

 

Aren't we all glad we paid attention in school when they taught that multiplication thingy?

I knew I'd use it someday for something.

Michael in KC

 

Anyone know if the gas tanks have to come out? I wonder if a public library would have the service manuals.

Maybe I will put it up on jack stands and remove the inner fender liners and see if the sensors are accesible. But it does not sound like fun to have to drain the gas from the tanks.

Someone posted last year that he removed the sensors, cleaned them to remove the sulphur deposits, and reinstalled them.

 

Keppler,

Here's a thought that may be totally off base, but I just thought I'd mention it.

My father-in-law had a 90 Chevy Celebrity. That car was designed with the fuel pump inside the gas tank. Lord knows why. Anyway, his fuel pump went bad and he found out that it was cheaper to replace the tank than to replace the pump. I'm just wondering if this is something you're going to do yourself or if you're planning on having it done by a shop. You might check to see if replacing the tanks would be cheaper than replacing the sensors.

Like I said, I may be way off base, but I thought I'd pass it along.

Michael in KC

 

My gas gauge is also a little finicky in the last 1/3. The C5 holds 18.5 gallons. I usually fill up at 285 miles on the trip meter regardless of what the gas gauge says.

 

Was that problem more common in the 02? Or did the 01 have something similar?

Michael in KC

 

Michael,

I just found two TSB numbers relating to erratic gas gauge readings. I cannot get the text but I will bring the numbers to the dealer.

If the sensors are accesible I would change them out myself, but I do not want to drop the tanks. I imagine some sort of calibration would be required once the sensors are replaced.

Still cannot find out if the tanks must be dropped. Last summer the dealer told me that in order to drop the tanks the rear suspension and differential comes out first. That is why they quoted $1,100 in labor. I did not have the work done because I did not want the entire rear end to be disassembled. Then another guy on this forum said 2002 cars were unique in that the tanks do not have to come out to replace the sensors. And someone else said the tanks can come out the side wheel wells leaving the driveline intact. I have conflicting information and currently I am unsure which is correct.

Thanks.

 

http://www.corvetteactioncenter.com/...el+Tank+System (This link may not work, you may have to copy/paste this.)

Wow, just found this. For those interested this article describes the entire fuel tank system for C5's. It says if you are experienced you may not have to drop the driveline. Mainly the article describes 2003 and 2004 cars. I will have to study this article. The C5 fuel system is very complicated because of the dual tanks.

The fuel gauge problem is common to a few years. I do not recall the specific years. But I would recommend adding a bottle of Techron or Sea Foam every 2-3 months. You do not want this problem.

 

If it isn't clear yet for anyone, yes the tanks must be removed in order to change the sensors.

 

This is out of the service manual cd for my 98. You don't remove the tanks, but you do remove the fuel tank strap/shield and therefore have to support the tank.

I'm having the same issue, so I'll be tackling this one in the near future.

Fuel Sender Assembly Replacement
Removal Procedure (Left or Right)
Tools Required
J 34730-1A Fuel Pressure Gauge
J 37088-A Tool Set, Fuel Line Quick Connect Separator
1. Disconnect the negative battery cable.
2.Relieve the fuel system pressure. Refer to the Fuel Pressure Relief Procedure .
3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
4. Remove the rear wheel and tire assembly. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
5. Clean all of the fuel connections and the surrounding areas before disconnecting the fuel pipes in order to avoid possible contamination of the fuel system.
6. Drain the fuel tanks. Refer to Fuel Tank Draining Procedure .
7. Mark or identify each fuel pipe in order to aid in installing the pipes in their original positions.
8. Disconnect the quick-connect fittings from the fuel sender. Refer to Quick Connect Fitting(s) Service (Metal Collar) or Quick Connect Fitting(s) Service (Plastic Collar) .
9. Cap all of the fuel pipes.
10. Disconnect the fuel sender electrical connector.
11. Remove the fuel tank strap/shield.
12. Support the fuel tank.
13. Remove the fuel sender attaching bolts. Remove previously installed "break-away head" service bolts using a 5/16 inch open end wrench.
14. Discard the fuel sender attaching bolts.
15. Remove the float arm retaining clip and the float arm (left fuel sender only).
16. Carefully remove the fuel sender with the gasket.
17. Discard the fuel sender gasket.
18. Clean the gasket sealing surfaces.

 

It seem that if you have to support the tanks, it just makes more sense to remove them where you can work comfortably.

 

The reason I want to find out exactly what is required is because when I go to the dealer I want to be knowledgeable.

I once had to have an EBCM replaced. The dealer quoted me $1,200 for the part plus $300 for labor. I checked online sources and found the part for $650. Went back to the dealer and asked if I bring the part in would you install it and also asked why are you charging me $1,200 for something I could buy for $650. The dealer offered the part for his cost at $700 plus $200 for labor. I did the deal because the dealers work warranted the repair for a few months. With a little knowledge I saved $600. I expect a similar situation.

I thought the original dealer quote of $2,100 was ridiculous to replace two gauge sensors. And did not like his assessment that the rear driveline must come out (thus the 11 hour labor charge) when I have acquired some information that this is not required.

Does anyone know if the rear driveline and suspension has to be dropped? I have conflicting information on this.

Thanks all.

 

The search feature is a powerful tool.

http://forums.corvetteforum.com/show...+gauge+reading

 

Spent half an hour at a public library. They have Alldata technical references available online. Both Alldata and Chilton's say the same. RJ1AZ is correct. The tanks do not have to come out. The rear driveline and suspension do not have to be dropped. The tank supports are removed, the tanks are then lowered, and supported in place to access the sending units. The tanks are accessed through the wheel wells.

I printed out 10 pages of detailed instructions to remove and install both sending units. I also printed out TSB 02-06-04-010A, dated June 27, 2003. It covers model years 1999 - 2002. The corrective action is to reprogam the PCM a new service calibration which became available June 2003. It states to use Techline(R) TIS version 7 or later.

I should have asked the library if I could email the bulletins to me and then I would have been able to post them.

Alldata gave the repair labor time of 3.5 hours for both sending units. (Recall the dealer quoted me 11 hours and quoted $2,100 for the repair.)

I only have to find the part numbers to search part costs online. And to decide if I should replace the fuel filters and fuel pumps while the fuel system is disassembled.

With all this information I will be prepared to intelligently discuss the repair with the dealer. I think I will go to a different dealer this time.

Another strange thing with this car is that the manual states it has a 18.5 gallon tank. Yet I run out of gas at 14 gallons consumed. My car cannot pick up the remaining 4.5 gallons.

I hope this helps anyone else who has this problem.

 

The service manual cd has all model years on it, so I looked up your year-2002, and the instructions for removing the fuel sending units is the same as what I posted earlier, for both left and right sides. No mention whatsoever of removing the tanks or dropping the driveline. I think your dealer service writer is looking to have you make his next boat payment.
Additionally, here is a step by step with pics that I found for removing the left side (that has the fuel pump) sending unit.
http://www.cajundude.com/racetronix.htm

If you take it to the dealer and your service writer tries to you that it's going to take 11 hrs and the driveline has to be dropped, I'd tell him you have a service manual and have studied the procedure already, and you know that's not necessary. His expression should be priceless

You might also want to make an inquiry here http://corvettemechanic.com/ and see if one of the technicians will tell you how long their labor book says the procedure should take.

 

I'm a day late and a dollar short! Looks like you've been busy and found everything you need.

I'll be interested to hear what the final cost is, because I'm getting sick of my gas gauge bouncing around.