Fluctuating oil pressure in '92 Mercedes 190E 2.6 while driving: Normal?

[thebourne_id]

I have a '92 Mercedes 190E I bought used and for the first few weeks the oil pressure gauge would work for the first minute after turning on the car and then drop to 0, which I knew was bogus because the car would read full oil at the dipstick. I took it to a Benz garage and sure enough the oil sensor was busted and they put in a working sensor. However when I drive now the car will have full pressure when I start up the car and when I drive, but at stops and red lights the pressure will droop down to 1/2 pressure and also dips to about 2/3-3/4 pressure during low speed cruising. The amount of pressure also seems to be affected by ascents and declines; higher on inclines and lower on descents so am I just observing normal fluid dynamics or something troublesome at hand?

 

[adiabaticfire]

that symptom can often be a problem in the electrical system of the dash board and such. could be a bad gauge, a bad solder joint, voltage regulator etc. if thats the only gauge that fluctuates its probably the gauge it self. could be a problem with the engines oiling system but most of the time that stuff is really solid since oil is that important. my cars oil gauge goes anywhere from 0 to 90 while driving and i don't worry about it since it has a good oil pump design. it is also normal to drop a little at low speeds anyways.