Fixed my fuel gauge - 300E!
 

My fuel gauge battle has ended.

Finally, I can once again be cogniscent of the amount of fuel in my car, no longer shall I be a slave to the dreaded "past-the-1/2-way-mark" jumping needle. No more warning light/watching my mileage driving for me.

It was the fuel level sending unit after all.

The history - I bought the car and it already had the fuel gauge problem. Needle read fine from full to half, then lower than that it began its deceptive little dance. The low fuel warning light always worked and that, along with resetting my trip meter, was my way of measuring fuel.

After reading posts here, I removed the sending unit from the tank, dismantled it and inspected it. It looked clean - no visible deposits. I gently wiped the wires clean and tested the floater. It seemed to work. Put it back in, same problem. Suspected the gauge itself. Removed instrument cluster and inspected. Everything seemed A-OK.

Recently bought a new sending unit from my tech. Didn't fix problem. Utterly gutted at this point and frustrated. Sent VDO an e-mail asking about inherent Mercedes gauge problems. VDO said no inherent Mercedes gauge problems thank you very much.

Last night my tech called me and said he had another new fuel sending unit that had been ordered by a customer but not picked up and suggested I try it just in case. I dropped by the shop, we swapped the sending units and viola - a perfectly working gauge!

The original replacement unit must have been faulty. My tech was not too happy and felt bad about it so he offered me a free tuneup.

Suffice to say, I'm a happy camper and it's weird to now have a normally functioning fuel gauge. I'll have to re-train myself to use it! Ah, the little things.

Hmmm. Very interesting.

I replaced my sending unit as well with no effect.
Perhaps I got a bad one too!

One thing I did notice was that the first replacement unit came shipped loose in a box. The second unit came in a carboard tube and was held in place by two pieces of foam that held it suspended in the center of the tube, so that it did not touch the walls of the tube. Much better packaging.

Agree with csnow. I had mine replaced and after two fillups or so it started jumping after it reaches the half mark. Gave up and decided to live with it.

I fixed our sending unit, and it has performed fine now for quite awhile. Cleaning the slidewires did the trick - but not the first shot at it using only solvents. Abrasive cleaning was needed - i.e. a pencil eraser on the wires and all contacts, followed by isopropyl alcohol.

Steve

Yeah, mine had the nice packaging. Still no good.

I wonder if using some light-duty steel wool would clean the wires enough?

Haasman