Quattrodude

Just wondering if anyone has any ideas -

I filled up my tank the other night - topped it off (lucky so far no gas leakage from the dreaded sending units) with no issues - Gas marked to 1 bar from the very top.

Drive home - and it was down 1 bar - I live less than a mile away - So i just marked it up to maybe they did not do a good topping it off.

Next day I drove to work and was down 2 more bars (only 15 miles to work - MGP showed about 16mpg)...

By the time I got home (total 29 miles round trip) I was at 1/2 tank and was like WTF??? where did all my gas go?

I have checked the floor of the garage - nothing
No smell of gas inside or around the car
The gas cap is on tight and no smell or residue of gas
No smell of gas from under the hood
No shredded rear tires (checked lead foot - not that heavy)
The car seems to be running fine that I can tell?

Normally I get a 8-10 days of daily driving from a tank...

Anyone have any thoughts or clues?
Would a bad O2 sensor make a car run that rich? (even though it does not seem to be running rich)

Not sure if I should be driving it with the bars dropping so fast! It has to be going somewhere???

Thanks all in advance for ideas

PACougar

It sounds to me like you have a issue with the gauge or sender and not that you're actually missing any fuel.

theunderlord

^ +1.

Quattrodude

Interesting - never thought about that..

But when I get home tonight I'll go and fill it up and see how much it takes...
(i did not drive it today)

urbamworm

Yeah it sounds pretty obvious to me that the sendor is bad. I mean you have lost 7, 8, 9 gallons of fuel and smell no gas, obviously the car would be reaking of it so the sendor has to be bad. You could always go to the gas station real quick and top it off to confirm this very easily.

Edit: posted while I was typing.

PACougar

I've never heard of anyone siphoning gas while you drive It sure makes me think though.

vioilio

go back to the gas station. top it of again. see how much fuel (gallons) it will take. Divide the distance traveled from your last top off untill now with the gallons you just put and there you go... old fashioned method of calculating MPG.

kompressede

If you were located somewhere that Sandy just recently hit, I would say somebody is siphening your gas?

No codes? Are you up to date on the maintenance?

Quattrodude

No codes - only thing I did about 3 weeks ago is swap all the spark plugs...and she runs soooo smooth now...But would of figured better milage not worse...And the last tank of gas seemed normal.

(Luckly - I'm west coast so gas is "cheap" - I think about $3.69 for Cheveron Super)

And the gauge dropped that fast while I was driving...and I could net see anyone running next to me with a jerry can...LOL

(Maintenance - umm I need an oil change prob - I'm about at 6K miles...not sure what else I would need?)

Oh and I have about 59K on the clock...if that helps?

sloanbj

Are you a lead foot? Or perhaps you have the parking brake engaged?

Jakpro1

Plus our cars are really hard to siphon from. Benz has some weird thing in there. I gave up trying to and just drained from fuel rail port one time

03'55AMG

That's weird, did you ever top it off to see the gas used? And parking brake can't be on. You go more than 3 miles an hour with it on, and you'll know, believe me.

Manuyc

Wow that a lot of gas consumption

03'55AMG

Cheap? Dang gas here is only $3.10. Crazy cheap

WPOZZZ

I hate you guys. I paid $4.35 at my last fillup a couple weeks ago.

Quattrodude

Ok - so I go and start my car (let her warm up in the garage) Saturday morning to go fill her up and see. And it shows me 1/2 tank. I checked the floor - smelled for gas in all the places one would expect gas....no oders other than leather smell.

So I back out of the garage and and am 2 blocks down the street and PING - 2 bars from the top!

So sounds like its more the sending unit...So the fun question...

Since I dont think i have any dreaded fuel leaks coming from the back seat - should I just leave alone? I think I would rather have a misbehaving gauge vs leaking gas? What would you do?

And is the sending unit - use a float? that maybe it just stuck (crossing fingers)? I could get it possible fixed under warranty if I could replicate the problem - but that could be fun to prove if even worth it.

(Maybe I need to do more some more vigerous driving and shake that tank!? )

Cheers

DVC

Maybe park the land yacht and take the UrQ

Infamous 1

Did you have the recall done for the sending unit?

Quattrodude

I'll have to check with the dealer - Not sure - I have only have the car 1.5 years and so far had very few issues with it.

Thanks!

C280 Sport

Use the computer in your car that tells you distance on your tank of gas and also check your MPG as well. I had a fuel sending unit on a MB and had a similar issue as you before.

AgSilver