Sounds an awful lot like guide rod mounts.

But, since you replaced them with used ones, I can't see how that could be .

Take another look at the, uhm, guide rod mounts.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.