I experienced the same thing yesterday after changing my oil, I made the switch to Delo 400 from Delvac Super, both are 15W-40 oils.

At idle, my oil pressure light would come on, but with a slight blip of throttle, it would go off. I noticed that after a long hard drive in 49c weather. I am going to change the oil pressure switch to see if this goes away.

I have a Trax Gurkha which has the OM 616 turbo engine.