1990 740 GL fault code 123 engine temp sensor.
Is this the one that looks impossible to get at under the third injector
on the head?
If this is the one can it be removed and replaced without pulling half
the engine to bits?

F Murtz wrote:

I believe that's the one, there's two though, one is for the gauge and
one is for the ECU.

If you take the intake manifold off the sensors are all quite easy to
get to. It's really not very difficult, though you'll want to have a
spare gasket on hand and take care not to drop anything down the intake
ports. I stuck paper towels in each one while I work.