Yikes! I'm getting extraordinarily bad gas milage.

Mark Jacobs · 10-02-2005, 01:30 PM

Help, por favor.
My trip computer says I'm getting 23-24 mpg on the highway but earlier today the gas supply needle fell to near zero after driving only 200-210 miles on a full tank! Could there be a gas leak? I changed the timing belt, filters, etc. at 60,000 and 120,000 miles. FWIW, I'm hearing a whirring noise coming from the rear wheels that I hadn't heard before.

Thanks,
Mark (Jimi Ray Clapton)

paulroad · 10-02-2005, 03:07 PM

we know the Data Sceen is off by about 10%

Mark Jacobs · 10-02-2005, 03:24 PM

...but I'm not sure. The trip computer says I'm still getting respectible milage but the gas needle is setting into the sunset at 200 miles after a fill up. It just seems as if the gas disappearing so fast now. My 01 ar has 167,000 miles on the odometer. Think that has anything to do with it?

The other thing that spooks me is that sound from the rear. I'm open to suggestions. Think a gas additive might help? Whch one?
Thanks

paulroad · 10-02-2005, 04:48 PM

paulroad · 10-02-2005, 04:50 PM

But with 167K on it it can be anything. The sound I have no clue. And yes 200 miles to a tank.. if its highway and town is N/G. Have you checked your oil consumption?

TurboBob · 10-02-2005, 09:19 PM

I've had them fail on a couple of cars, and they don't just quit completely. They can just start giving you all kinds of readings. No idea on the noise though.

Troy H · 10-02-2005, 09:44 PM

B5s, so it's not a stretch to think some of ours may fail too. There's a write-up on how to fix it in the tech section. Took me only about an hour on my A4.

RMcQ · 10-03-2005, 04:30 AM

Perhaps you drove away thinking you were full and never looked down at the gauge until much later??

Just a thought of a perhaps simple explanation.

If the mileage is actually bad and there is a noise at the rear wheels I would jack it up and check that they rotate freely.

I would also do some measuring by calculation of mpg and make sure that you are as empty as you think you are when you fill up. When my car goes to "0" on the miles of gas left on computer with gauge on "E" it will a little less than 18 gallons.

xtreetoes · 10-03-2005, 06:03 AM

is really 3 sending units. One on each side of the take and one by the filler tube. You need to replace them together and cost over $300.00 IIRC. There were issues with the material used in the sending unit but our allroads have the new design.

I had to do a little research on this a while back. My gage stopped working. I did the Bentleys test and my sending units were fine. I pulled the instrament cluster to check the resistance and when I put the cluster back in all was ok and has worked fine since.

10-02-2005, 03:07 PM	#2
paulroad AudiWorld Super User Garage is empty, add now Join Date: Oct 2003 Posts: 18,425	So when you illed it up..what MPG did you get.. we know the Data Sceen is off by about 10% __________________ 4/23/11: S4 Premium Plus, S'Tronic, Nav, Titanium body Original Ride: • Bought New May 2003 allroad 2.7t 6 Speed • Sold @ 217,856 miles on April 23, 2011 -Mod/Repair Log 2400 Miles 5/28/11 New Conti Extreme DWS A/S Tires--smooths out the ride OEM Dipstick--Need to see and smell the oil OEM Rubber Mats--Look better than Stock Carpet and last longer

10-02-2005, 03:24 PM	#3
Mark Jacobs Audiworld Senior Member Garage is empty, add now Join Date: Dec 2000 Posts: 262	Prolly in the mid 20s Paul. ...but I'm not sure. The trip computer says I'm still getting respectible milage but the gas needle is setting into the sunset at 200 miles after a fill up. It just seems as if the gas disappearing so fast now. My 01 ar has 167,000 miles on the odometer. Think that has anything to do with it? The other thing that spooks me is that sound from the rear. I'm open to suggestions. Think a gas additive might help? Whch one? Thanks __________________ Formerly JimiRayClapton Limited Edition Fender Stratocaster 52 RI Fender Telecaster Parker Fly Custom Duck Dunn P Bass Gibson J-45 Rosewood Fender Hrd Deluxe Amp SWR Workingman's Bass Amp

10-02-2005, 04:48 PM	#4
paulroad AudiWorld Super User Garage is empty, add now Join Date: Oct 2003 Posts: 18,425	Re: So when you tallied it up..what MPG did you get.. __________________ 4/23/11: S4 Premium Plus, S'Tronic, Nav, Titanium body Original Ride: • Bought New May 2003 allroad 2.7t 6 Speed • Sold @ 217,856 miles on April 23, 2011 -Mod/Repair Log 2400 Miles 5/28/11 New Conti Extreme DWS A/S Tires--smooths out the ride OEM Dipstick--Need to see and smell the oil OEM Rubber Mats--Look better than Stock Carpet and last longer

10-02-2005, 04:50 PM	#5
paulroad AudiWorld Super User Garage is empty, add now Join Date: Oct 2003 Posts: 18,425	Chevron with Techron.. is what I've always used in the tank.. But with 167K on it it can be anything. The sound I have no clue. And yes 200 miles to a tank.. if its highway and town is N/G. Have you checked your oil consumption? __________________ 4/23/11: S4 Premium Plus, S'Tronic, Nav, Titanium body Original Ride: • Bought New May 2003 allroad 2.7t 6 Speed • Sold @ 217,856 miles on April 23, 2011 -Mod/Repair Log 2400 Miles 5/28/11 New Conti Extreme DWS A/S Tires--smooths out the ride OEM Dipstick--Need to see and smell the oil OEM Rubber Mats--Look better than Stock Carpet and last longer

10-02-2005, 09:19 PM	#6
TurboBob New Member Garage is empty, add now Join Date: Aug 2005 Posts: 344	Re: Could be bad sending unit, I've had them fail on a couple of cars, and they don't just quit completely. They can just start giving you all kinds of readings. No idea on the noise though.

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10-02-2005, 09:44 PM	#7
Troy H AudiWorld Super User Garage is empty, add now Join Date: Mar 2000 Posts: 13,491	Sounds to me like your sending unit may have failed. It was/is a common problem on B5s, so it's not a stretch to think some of ours may fail too. There's a write-up on how to fix it in the tech section. Took me only about an hour on my A4. __________________ "However I do realize that a woman, particularly one with whom you have exchanged marriage vows, can not be reasoned with using logic, examples, data, or any other means except to agree." - RMcQ "Any car that merely takes you from A to B does not go far enough." - August Horch Want to see my skills of an artist? I make detailing fun! Klicken Sie hier für meine Detailing FAQ: 2.0Tq DSG/Prestige/S-Line/MagRide/Heated Seats:

10-03-2005, 04:30 AM	#8
RMcQ AudiWorld Super User Garage is empty, add now Join Date: Mar 2000 Posts: 12,481	Any chance you thought you were full (pump clicked off) buy you were not? Perhaps you drove away thinking you were full and never looked down at the gauge until much later?? Just a thought of a perhaps simple explanation. If the mileage is actually bad and there is a noise at the rear wheels I would jack it up and check that they rotate freely. I would also do some measuring by calculation of mpg and make sure that you are as empty as you think you are when you fill up. When my car goes to "0" on the miles of gas left on computer with gauge on "E" it will a little less than 18 gallons. __________________ + + = 451whp/472 ft-lb Full RS6 bastardized allroad quattro alive and on the road.

10-03-2005, 06:03 AM	#9
xtreetoes AudiWorld Super User 2010 Audi A6 My Garage Join Date: Aug 2004 Posts: 11,405	allroad sending unit is really 3 sending units. One on each side of the take and one by the filler tube. You need to replace them together and cost over $300.00 IIRC. There were issues with the material used in the sending unit but our allroads have the new design. I had to do a little research on this a while back. My gage stopped working. I did the Bentleys test and my sending units were fine. I pulled the instrament cluster to check the resistance and when I put the cluster back in all was ok and has worked fine since.

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