udiaudi

Hi,
What are the symptoms of a bad fuel level sending unit?
I get a low fuel level very erratic reading. one minute it has 50miles to go. I'll park the car, next time it will show 10 miles to empty. Strange.
Thanks,
Udi

DWP

That's not as bad as some of syptoms I saw - from 250 mi to go to 50 mi left in 10 miles of driving!

stanatl

My gauge jumped from full to 1/2 full to 3/4 full to empty in the span of about 10 minutes. Then it just stuck on full. The trip computer was bouncing as well.

TheBrit

I've stopped my car one night after a cruise with 50 miles range and have had it start up with 5 miles in the morning! After a couple of miles of driving, I stopped (at a fuel station just in case!) and switched off and back on again. It came back with 25 miles range.

I suspect that the trip computer takes a reading quite early after startup and perhaps the sending units have not "woken up" correctly and send a low reading. I have noticed the needle on the guage seems to come up slightly more slowly when the tank is below 1/4 full, so perhaps the sensors are quicker to react with more fuel in the tank or something?

Anyone know how the sensors actually work - float gauge or pressure detector or something?

StealthMobile

When you start the car in the morning (especially a cold one), the ECU most likely calls for a rich mixture to ensure that the engine does not stall. Since the miles remaining is computed based on the fuel level and the fuel burn rate, the range will read "low" until the engine reaches operating temperature (and optimal fuel mixture). Without turning the engine off you should have seen the range gradually increase.

I have seen this after stopping for dinner along an interstate highway with a low fuel level. After returning to the highway the range increased by about 10 - 15 miles (from the startup reading) after a few minutes, eventually returning to within 5 miles of the pre-dinner range. This seems to be correct, given that I had driven about 5 miles in the meantime.

3rd audi

Like so many others posting on this forum, I too had the fuel guage gremlins. From full to empty, and everything in between! I actually ran out of gas once, even though acutely aware of the problem. SO.....one poster suggests swithching from whatever gas I was using to Union 76 gas. After 1 tankfull, the problem has never manifested itself again. Just to be sure, I switched back to Chevron gas, only to have the problem reoccur. Now, I know this makes no sense at all, but I am telling the truth. I would be very curious to discover whether or not you, or anyone else has found this "remedy" to solve the guage/computer problem. Please advise!

Finman

Most of those with bad fuel senders had problems with the fuel gauge itself being very off (eg. reading full as it approached empty).
The estimated range is a very rough estimate. Unlike some other systems that change by the mile, Audi's changes less frequently, but in larger steps, but is based on current fuel consumption rates (instant mpg). Neither one is particularly accurate.
I ignore this useless feature, I know I get 320-350 miles on a tank of "typical" driving and a bit more with highway only driving. Additionally, I know I get ~40 miles from when that f#*king alarm goes off before I think it runs dry.
Interestingly (slightly), mine never reads anything like 10 miles to empty. I think when it hits 40, after that it only has the low fuel symbol and I can't get it to give me an estimate, or it reads 0.
I think your sender is OK.

KL'00-2.7T

That is exactly my experience. Not a clue as to why 76 works well with the senders.

Audi G

Re: Union 76 solved my gas gauge problem

Audi G

Re: Try Union 76 if it is in your area