Fuel gauge on E320 not working properly

The fuel gauge on my 98 E320 is acting up. It registers full when I fill up the car. However, after a few miles, it drops to just over 1/4 full. It
stays at that reading until the tank drops below that level and then appears to be accurate again. Is this the gauge itself or the sending unit in the gas tank?
TIA,
Brent
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Sending unit most likely. As I recall, there were issues with this during that model year, most have failed by now and have been repaired.

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This is a very common failure, due to contamination of the sensor.
Add some injection cleaner to the fueltank, double or triple the dosage (but with full tank - so that all the sensor gets the treatment).
If one treatment doesnt help, repeat.
-- Thomas
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On Fri, 31 Oct 2003 14:51:17 GMT, "Brent Slone"

Sender unit, easy DIY job on a 210 E class (is it a saloon?)
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Yes, it is a saloon, or sedan, if you like. I'm going to try the fuel injection cleaner first, then replace the sending unit. Can it be accessed under the rear seat?
Brent
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On Mon, 03 Nov 2003 12:54:08 GMT, "Brent Slone"

Trust me, its the sender, the injector cleaner won't help. You access it through the boot, take the trim at the back of the boot off and you will see the sender in front of you, turn it 90 degrees counter clockwise to remove.
5 minute job, even for a novice
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On Fri, 31 Oct 2003 14:51:17 GMT, "Brent Slone"

I had to change two fuel sensors in my E240 until one worked correctly. Perhaps fuel contamination is an issue, but on the other hand sensors should be built to work well with a reasonable fuel impurity range.
WY
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