Renate, Unless you know the parish and/or suburb of Temeswar your family lived in, it would almost be impossible to check church records, not to mention cemeteries."Schlosser" is a German name and chances are they root from families from a village outside of Temeswar.I know of a few villages they are known to live besides Temeswar: Mercydorf, Lenauheim, and Uihei.
What documents do you have showing birth and marriage place as Temesvar?Have you found passenger records for your family?
At the Ellis Island site: 1908 Schlosser, Anna 2 Temesvar, Hungary 1908 Schlosser, Franz 32 Temesvar, Hungary 1908 Schlosser, Johann 6 Temesvar, Hungary 1908 Schlosser, Maria 30 Temesvar, Hungary 1914 Schlosser, Maria 23 Ternesvar, Hungary 1923 Schlosser, Rosa 23 Temesvar, Roum. These can be seen at a site I publish, associated with the DVHH: http://www.dvhh.org/timisquarters/registry/immigration/index-page-2-m-z.htm#Shttp://www.dvhh.org/timisquarters/registry/immigration/index-page-2-m-z.htm#S
Anyone researching their family roots of ethnic German background in former Austria-Hungary territories, is probably Danube Swabian / Donauschwaben. I invite you to check out the Donauschwaben Villages' Helping Hands (DVHH) Project http://www.dvhh.orghttp://www.dvhh.org, a volunteer project for researchers of Danube Swabian Heritage. We are celebrating our 4th year online, providing a wealth of information for you to utilize.