83 300TD Low Oil Pressure

[towjoe42]

The car had been stored for almost a year.
When I am at driving speeds with my 300 Diesel my oil pressure is at the top of the gauge.
When I slow down and come to a stop the oil pressure actually goes down to the bottom of the gauge.
I changed the oil and filter and that did not help keep the pressure up at Idle and low speeds.
I have another mercedes and it's pressure drops only a small amount at idle and stays steady.
Could the oil pump be starting to malfunction? Joe

[DebSol]

Should peg while driving, but shouldn't go below 1 when idling. How many miles are on the car?