This particular patent has been applied long ago. How can I find out if the patent has ever been granted or is still pending. If the patent has been granted, I want to know the date of it's issue.
You can use one of several search tools. One that I like is Espacenet run by the European Patent Office. I provided the application number (not the publication number) and this is the URL to get to the results.
Selecting INPADOC Legal Status from the list on the left gives a bare bones answer that on June 17, 1992 this application was withdrawn. You can probably get more information on a German patent office site or you can contact someone that works with German patents to give you more information.
Espacenet has a disclaimer that they try to have accurate information but notes that mistakes can happen. If this is critical to you, you should have your patent attorney dig a little deeper, most have relationships with European patent attorneys that are familiar with these systems.