1984 911 press gauge question.

[hyperkinesis]

Hi I'm having a question about the Druck press gauge on my 1984 911...
this gauge with the car off and the switch in on the show a pressure in 5
same happen when I turn on the car it goes to 5 very quick, then when I turn off the car it takes about a minute or 2 to get to zero again.
this is not normal?? what cause this problem, how I solve it

Thanks again for all the help

[djcdmv]

Oil pressure stuck at 4, not pegged at 5 (searched)

Had a similar problem. Read third post to test your sender. Replaced my sensor and all is fine.