I am in a fix..  engine in the sd developed a rod knock [I think]  and
I need this car really bad.  I have a good 300td turbo engine I can
use.

I would like to run this engine in the 126 till I find a regular sd
engine..  [besides I have a td I need this engine for.

Is it OK to just 'plug'/close off/ the lines to the hydraulic pump and
run it dry?

I assumed the oil filter housings were identical but for the oil gauge/
sender units, but upon trying to swap them, I see the 126 housing has
the little wheel/spring thing mounted near flush to the housing as
opposed to the 123 housing, this plastic finned wheel is indented
about a quarter inch.  What is this thing?       4 little fins,
plastic?        looks like it turns, but what turns it?       On one
of the housings the little fins on this wheel are broke off..  are
they swapable?

Anything else I should know?  This groups help has been greatly
appreciated in the past..  good folks here..  :)  TIA  -Gary

Ps..  on the 126 rod-knock noise, it is really really huge..  I pulled
the valve cover and hoped to find a loose rocker or something but all
looks normal..