Oil Filter

["Mike Kofal" <mkofal@csn.net>]

| 
|  Third, OK...OK...I now use the original equipment Audi oil filter with 
 
| check valve...I'm the FRAM bastard, remember?  Is Mann supposed to be   
| better or same?
| 

Whoops!  I just bought a used '92 CS100Q and took it down to one of the 
local quick lube services for an oil change.  What should I know about the

oil filter?  What does the check valve do?  Assuming they put a basic 
Fram filter on, should I immediately go to the dealer and get one with 
the check valve?  What would happen if I didn't?