Mercedes: 1993 Mercedes Benz E-320, oil pressure guage, instrument clusters

Question
Sir,
why does the dashbord oil pressure guage don't stay steady & dances? I knoe it's supposed to be at 1.5 mark when the car is running in park & goes up to 3 when driving. but as I'm in park, it changes from 1.25 to 1.5 continously! please advice. another question- why would the fuelk guage in the dashbord also starts going up & down as the fuel tank gets to 1/4 full?  

Answer
This sounds like a bad ground.

You may try DIY repair.

Just sharing: My Dash Lighting Project
http://www.mercedesshop.com/shopforum/showthread.php?p=781406

no dash lights, flaky tach, temp and fuel gauge not working...what gives?
http://www.mercedesshop.com/shopforum/showthread.php?t=141148

Who Rebuilds or Tests Instrument Clusters?
http://www.mercedesshop.com/shopforum/showthread.php?p=510680

300D Instrument Cluster Lights
http://www.mercedesshop.com/shopforum/showthread.php?t=65955

How to remove instrument cluster.
http://www.mercedesshop.com/shopforum/showthread.php?p=176202

Lets' Pull the Instrument Cluster!
http://www.mercedesshop.com/shopforum/showthread.php?p=447830