Did a search - no luck. This car is new to me, so I am still learning....

Can anyone tell me where the oil pressure needle should be when the engine on an 80s S-Class is fully warm and the car is idling in park? Also, what about when in gear? My car idles in gear at 500rpm. Is this RPM to low? I am just wondering about the oil pressure, because I am not sure where it is supposed to be. When cold, it tops out past "3" and even when warm when I accelerate it goes past "3". When idling in neutral, it is around "2" and when idling around 500 rpms it is between "1" and "2". I know my oil is old and needs changing, so that may make a difference.

Now, what about the temperature? When in slow/stopped city traffic, it is just below 80*C. When driving on the highway, it is between 80*C and the first line. Sometimes, it is just above the first line. Heat is hot however. Everything seems fine. I just want to know if this is normal operation.

Also- my middle muffler has a hole. Is this something that is going to cost $$$, or can a local independent shop just install a "standard" muffler? I guess I could call tomorrow, but wanted to get a bit of info here tonight about it.

Thanks!