Mostly my fuel gauge needle is stable from it jumps around from time to time maybe 1/16 to 1/8 inch. I could be on a flat road (not a hill where the fuel in the tank goes to the back of the tank) and the needle jumps occasionally, then back up. When I fill the tank up, the needle goes up and when the tank gets low on fuel the needle goes down but it's jumping too much for me to depend on it.

What's causing this? Years ago I took the fuel gauge sensor out of the fuel tank and got sludge off the wires that the gauge rides up and down on.

1991 300d, 224k

Time to clean the crap off the wires again.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

I previously cleaned the crap off the wires on the fuel gauge sender because it wasn't working at all; the car had sat for years before I bought it. Now the fuel gauge sender works, but it's starting to jump around some.

No, that was the answer. Clean the wires well. Clean the slider that goes up and down too. Be gentle. Varnish and oxidation make a poor connection that makes the gauge flick around.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

BE GENTLE with it ! .

I managed to snap one of thise hair thin wires by rubbing too hard .

I now use Rollguy's SAMS CLUB cleaner / degreaser and a *very* soft 1/2" paint brush plus a toothpick to get the little tiny bits of fungus out of the top part and the contacts on the lider .

I just did the one in my 1982 240D because that damned needle jittering drove me crazy (er) .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

If you brush on some water based paint striper gently and then rinse off you will have shiny new wires with no varnish. This method allows you to remove the build up without rubbing.

When I purchased my 95 E300D several years ago, the fuel guage would bounce around.

The fuel gauge bouncing went away after I put a can of Sea Foam into each of my 1st two fill ups. I had not expected that result, but it happened, and has not occurred again.

I don't regularly use Sea Foam but still add a can every couple of years. I also try to find diesel with a little Bio-diesel blended in, that probably helps to keep the fuel system cleaner plus the extra lubrication that bio-diesel provides.

If you find that the group grope has failed you, try this:

http://www.peachparts.com/shopforum/diesel-discussion/394040-solutions-some-odd-dashpod-problems.html#post3826962