I'm convinced that there is a defect in some MB fuel gauges. In all three MBs I've owned - 1971 250, 1977 280E, 1989 300E - the fuel gauge has had the exact same problem. It shows full to half fine but from half to empty, the gauge dances around. The low fuel indicator light is constant and works well (that, combined with my trip meter is how I measure my fuel consumption). I find it odd that all three cars from over 3 decades have the identical problem!

I've checked the sending units in the tank, with advice from this forum, and they've all been squeaky-clean. The floats slide perfectly. In one case (the 280E) I replaced the sending unit and still had the problem.

I recently contacted VDO with a description of the problem and here's the reply -

Hello Chris ,
we here are not aware of any problem with the MB fuel gauge . However if you need service to be done , please check with our service centers here :

http://www.vdona.com/Tech%20Support/repairpage.htm

these companies may find something in you cluster .

Mit freundlichem Gruß/Kind regards

Klaus P. Bornhaeuser
Manager Technical Support
Siemens VDO Automotive AG
188 Brooke Road
Winchester,VA.22603
Tel. 540 678-XXXX

I'm still not convinced. A thread in this forum mentions that re-soldering the cold solder joints in the back of the gauge in the instrument cluster can fix the problem. That will be my next step.

Still, I remain convinced that these gauges have an inherent fault. I've never had a problem yet with the oil, tach, clock, speedo, etc. Even the "economy" gauge works well. Too many people seem to have this same problem..there must be something to it. Anyway, I'll see how the soldering goes...

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Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

Zeus, I wholeheartedly agree with you!!

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

The fuel gauge sender in my mom's 97 E320 had to be replaced under warranty.

The fuel gauge in my 97 C280 occasionally gives the wrong indication, but works most of the time, I strongly believe that the problem is with the senders (two of them in the tank). I'm not too worried, though. When it does act up, usually once per tank of gas when the tank is around half full, it dances around and gives wrong indications for no more than 30 seconds. Although it has not done so in about a month.

I agree with you that there must be some type of common problem with them. When I called the dealer to get a price quote, they said they have plenty of them in stock, as if it such a common repair that they know to keep a stock of them.

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

I had the same problem on my 87 420sel and it was the fuel sender unit. It is easly repaierd, thank god cuz a new one was over $100. Remove the sender from the tank. Open it, and you will find a float that mover a shorting bar between two small wires. These wires act as resistance elements. The shorting bar slides up and down along the length. The resistance changes and the guage moves as a result. The problem is that the wires get coated with varnish or something. Using steel wool (very fine 000) gently polish the wires to remove any deposits on them. They are delicate so be careful. The shorting bars which are gold plated now make good contact and the problem should be solved.

Hope it works for you.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Hi Dave,

I've cleaned the fuel sending units several times and in one case replaced the entire unit with a new one. Problem still persists. That's why I contacted VDO. I sincerely think the gauges have an inherent fault. Especially since the upper range of the fuel gauge reads fine, it's only the lower half that starts dancing...weird.

__________________
Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

Many times on early cars the wiring at the tank sensor crack & you can get that dancing.
Just remember that this is only a variable resistor & over time they ALL will wear out.
The newer cars ie; 1995 & later DID have a design problem and they say it is due to the LOW EMISSION gasoline that is used here in the US.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

The problems I have had occur on Diesels, not gas cars, and makes the last half of the gauge meaningless. The reserve warning light works ok, but the jumping guage is a pain in an otherwise very sound machine. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

According to another poster, please don't use even fine steel-wool or emergy cloth to clean connectors.

Microscopic bits of steel-wool get embedded and corrode. Confirmed by a microscopic visual inspection. Erasers are also a no-no for an electrical cleaner as well.

He suggsted using a 3M "red" Scotch-brite which leaves no particulates, followed by a dose of the proper DeOxit for either "tin" or "gold" plated connectors.

Good luck,
:-) neil
1988 360TE AMG
1993 500E

My '87 300TD is starting to do the same thing. The gauge works well until about a 1/2 full. Then the needle on the gauge flips back and forth from empty to the "actual" level. Will check sending unit first.

__________________
1987 300TDT 165K MILES

The gauge on my 'gas' car does the same. Only when below half a tank, it sometimes dances. No other indicator does the same.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

You'd think that if it was deposits on the wires of the sending unit, it would affect the entire gauge and not just the lower half? Granted, there is usually more gas in the lower half for longer periods that the upper half, but still?

So, is it the gauge that is faulty or the sending units?

This is definitely a common problem that doesn't seem to have a simple solution...

__________________
Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

The W202 has two fuel tanks (hence two senders). It sounds like your problem occurs at the point when feed switches from one to the other (I am told this is how it works, rather than drawing from both simultaneously). Unfortunately the tanks have to be dropped on the W202 to replace the senders. I've just had mine done today under warranty (guage showed empty when tank was very full, probably a sticky float).

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JJ Rodger
2013 G350 Bluetec
1999 SL 500
1993 E300 diesel T
1990 190