oil drops from 3 to 1.5 , when in hard left turn??
 

just noticed this happening in the last week, on sharp left turns at low speed ( under 25 mph) i see the needle drop from 3 to 1.5 than when out of the turn it jumps back to 3. i tested it in right turns and have know problem.
oil level is at the full notch first thing in the morning before start up
using 5w-30 delo, 2000 miles on this oil change
:)

i did a couple of searches but didn't find this happening in other "low oil pressure" questions...

I'd suspect the oil guage sensor mechanism takes jolt into temporary air pocket, thats all. Think of it as shock absorber indicator that you might need new shocks, lol.

Wait as minute here! There is no sensor if it is a 240D, in terms of an electrical sensor.
The gauge reads actual oil pressure at the filter cannister where pressure is coming from the engine, so I think maybe the oil pump is not getting oil in a sharp turn, the level may be lower than the dip stick indicates, or something else related to the oil.
I would certainly pursue this to prevent possible damage to the cam lobes or worse! In San Francisco a driver of a diesel once stopped on a steep incline at traffic light. The oil was low. After only a minute or two the engine started making a noise and ultimately it had to be torn down to fix the noise, according to a mechanic I know. I don't know if it was uphill or downhill but that removed oil long enough to score a bearing or something. my-two cents!
Dieseldiehard